Abstract: Al-Shabaab has become one of Africa’s deadliest terrorist groups in recent years through its use of improvised explosive devices, or IEDs. Technological sophistication from abroad, especially from al-Qa`ida in the Arabian Peninsula (AQAP) in Yemen, may explain some exceptional recent attacks. However, al-Shabaab’s purge of external influences, reliance on local materials, and refinement of bomb deployment all indicate the importance of local expertise in its current IED campaign. Responses focused primarily on breaking international ties or taking out tech-savvy foreign-born or foreign-trained bomb makers are therefore unlikely to be sufficient or to succeed.

On October 14, 2017, Somalia suffered its largest terrorist attack in decades when two truck bombs exploded in the capital city,1 killing at least 350 people and wounding hundreds more.2 While unclaimed, it is likely the work of al-Shabaab, and the attack—the 33rd car bombing in Mogadishu in 20173—highlights the terrorist group’s increasing explosives capabilities. Al-Shabaab has become one of Africa’s deadliest terrorist groups primarily through a precipitous increase in the use of improvised explosive devices (IEDs). Al-Shabaab’s record 395 IED attacks in Somalia in 2016—almost 11 times the number in 2010 and nearly a 50-percent increase over 2015—more than doubled IED-related injuries and more than tripled IED-related deaths over the previous year, according to a recent study by Sahan Research.a Al-Shabaab also managed to carry out only the third recorded suicide terrorist attack on a commercial passenger flight, bombing a Daallo Airlines flight in February 2016 with an IED sophisticatedly disguised as a laptop.

The rise of al-Shabaab’s IED attacks is often seen as the result of a technology upgrade going hand-in-hand with the organization’s growing international connections. Emerging from the Islamic Courts Union (ICU) around 2006, al-Shabaab progressively affiliated with al-Qa`ida and conducted attacks abroad against targets in Kenya, Djibouti, and Uganda. Today, al-Shabaab’s ties to al-Qa`ida’s affiliate in Yemen remain the most consequential of its international links. Yemen, long a source of fighters for al-Shabaab,4 has become a source for IED detonators and detonating cords.5 Moreover, the analyst Katherine Zimmerman stated in U.S. congressional testimony that al-Qa`ida in the Arabian Peninsula (AQAP) “almost certainly provided the equipment or the expertise for al-Shabaab’s 2016 laptop bomb” on the Daallo flight.6 The same year, Somali Foreign Minister Abdisalem Omer “cited the use of laptop explosives as well as the ‘sophisticated engineering’ of truck bombs that are now leveling buildings ‘four or five blocks’ from the site of the blast as evidence of heightened collaboration between al-Shabab and AQAP.”7 Furthermore, the U.N. Monitoring Group on Somalia and Eritrea reported in October 2016 that al-Shabaab has “used increasingly sophisticated improvised explosive device technology in its operations, facilitated by the continued arrival of foreign trainers, and involving the transfer of knowledge from other conflict areas.”8

But the tendency to understand the growth in al-Shabaab’s lethal IED power primarily or exclusively through new technologies imported through intensifying international contacts is incomplete. This interpretation overlooks important actions taken to limit and reduce foreign influence in recent years. The situation today is unlike a decade ago when foreign influence within al-Shabaab was quite significant. Even before the group emerged, there were reports of the presence of foreign fighters in training camps run by al-Shabaab’s precursor militia in the ICU.9 Early on, veteran al-Qa`ida foreign fighters with experience in Afghanistan occupied key positions within al-Shabaab’s leadership. They were instrumental to the introduction of guerrilla tactics, such as suicide attacks, and they played a major role in training al-Shabaab members in bomb-making and other IED explosives skills.10 Saleh Ali Saleh Nabhan, an al-Qa`ida East Africa member, trained al-Shabaab fighters in asymmetric tactics, including suicide bombings and advanced explosives.11 Conflict in Somalia drew foreign fighters of diverse backgrounds, skills, and experiences. Al-Shabaab embraced and encouraged their arrival,12 and a sharp increase in IED attacks followed in 2007 and 2008, likely a result of mounting foreign fighter influence.13

However, the foreign influence reached something of an apex around 2010. Counterterrorism pressure intensified, stoking concerns among terrorist operatives about outsiders and spies, and broader disputes within al-Shabaab over strategy, ideology, and leadership came to the fore. Emir Ahmed Abdi Godane eventually moved against challengers and eliminated critics,14 including high-profile foreign fighters. By the end of 2013, through a combination of military action and internal housecleaning, key al-Qa`ida-linked international figures in al-Shabaab—Fazul Abdullah Mohammed, Bilal al-Berjawi, Omar Hammami—were dead, leaving the remaining foreign fighters cowed.15 In subsequent years, more attractive theaters for foreign fighters (like Syria) arose, al-Qa`ida may have adopted a less-centralized organizational model,16 and Somalia’s conflict entered a phase of increasingly internal and clan-based dynamics.17 While it continued to integrate foreign fighters, none from the sizeable Kenyan contingent, for example, achieved a top leadership role.18 Today, al-Shabaab occasionally directs some recruits from Ethiopia, Kenya, Tanzania, and Uganda to return to their homes to fight,19 and the group continues to execute foreign fighters on accusations of spying.20 The destructive capacity of al-Shabaab’s IED attacks significantly increased in the same period that there was a purge of foreign fighter influences in the group, suggesting there is more behind this trend than the “continued arrival of foreign trainers” and “transfer of knowledge from other conflict areas.”

Moreover, al-Shabaab operatives do not need to go abroad for basic IED materials, most of which are sourced locally. In addition to unexploded ordnances that litter the country after a quarter century of conflict,21 al-Shabaab gets IED main charges from its enemies in Somalia. According to a recent IED assessment, about 60 percent of the explosives contained in al-Shabaab attacks along the Kenyan border come from counterterrorism forces, obtained either from sub-munitions dropped by Kenyan war planes or through plunder of the African Union Mission in Somalia (AMISOM).22 Al-Shabaab has successfully overrun several AMISOM forward operating bases (FOBs). At one point, the group attacked three AMISOM FOBs in seven months—Leego in June 2015, Janaale in September 2015, and El-Adde in January 2016—and made off with large quantities of military equipment, weapons, and explosives.23 In January 2017, al-Shabaab once again overran a Kenya Defence Forces FOB at Kolbiyow and claimed to have captured military vehicles and weapons.24

A Somali man reacts at the site of a double-truck bombing at the center of Mogadishu, Somalia, on October 14, 2017, which killed at least 350 people. (Mohamed Abdiwahab/AFP/Getty Images)

Access to military materials has meant that al-Shabaab most commonly uses military explosives as its IED payload, notably cyclotrimethylene variants such as military-grade RDX.25 When military sources for main charges are unavailable, al-Shabaab substitutes them with TNT harvested from highly explosive artillery shells or anti-tank mines26 or with fertilizer (seized from farmers or purchased at local markets), which is legally imported and widely available in Somalia through aid organizations promoting agriculture.27 Al-Shabaab gets many other IED components locally as well. Motorcycle alarms and mobile phones, commonly used as triggers, are inexpensive and readily available at Mogadishu markets, as are pressure plates mounted on top of a spring—typical triggers for IED landmines.28 None of these components are beyond al-Shabaab’s budget. If early on al-Shabaab relied on financial support from external charities, the diaspora, and Eritrea’s sponsorship,29 the group today is far more self-sufficient, overseeing a remarkably effective ‘taxation’/protection system across south-central Somalia30 and making money off illicit trade in sugar and charcoal,31 as well perhaps as kidnapping for ransom32 and piracy.33 Through seizure and purchase of materiel available in Somalia, al-Shabaab has all the pieces it needs for IEDs.

Finally, al-Shabaab’s IEDs are becoming more deadly and complex, but the growing impact of attacks comes not just from imported technology, but also from innovative deployment. Notwithstanding the U.N. Monitoring Group’s finding that al-Shabaab is using “increasingly sophisticated improvised explosive device technology,” most of the group’s IEDs are not particularly technologically advanced. Setting aside outliers like the Daallo laptop and the recent Mogadishu truck bombings, news reports suggest that when “compared with IEDs found in other parts of the world, the al-Shabaab IEDs are of relatively poor quality and construction.”34 IEDs recovered from Somalia feature crude triggers, such as “pressure plates rigged with metal sheets separated by pieces of paper, pressure plates using saw blades, and bombs rigged with salvaged rocker switches like those found in a house to turn the lights on and off.”35 In fact, the quintessential signature design feature of an al-Shabaab suicide vest includes simple “male-female quick-connect devices such as those used in car stereos, or white plastic rocker switches.”36

The key evolution is that al-Shabaab has become more adept in its deployment of bombs, tailoring its IED attacks through refined tactics, techniques, and procedures. In ambushes of security convoys and patrols along main supply routes, al-Shabaab strategically positions the IED to stop vehicles in a pre-determined ‘kill zone’ exposed to small-arms fire and rocket-propelled grenades. To defend its own camps, al-Shabaab sets out systems of multiple IEDs, either linked together in a daisy chain or detonated separately and arranged for area saturation. Yet another technique involves sending vehicle-borne IEDs (VBIEDs) or suicide vehicle-borne IEDs (SVBIEDs) to break through a security perimeter, followed by fighters with small arms and light weapons, sometimes wearing IED suicide vests, to enter the breach and kill large numbers before dying themselves. This IED tactic has been used against FOBs, official buildings and compounds, and hotels and restaurants in Mogadishu and other parts of southern and central Somalia.37

To punish first responders and to inflict maximum damage at soft targets, al-Shabaab has developed still other approaches of deploying secondary IEDs in complex secondary attacks, like those conducted against the Ambassador Hotel and Naaso-Hablood Hotel in Mogadishu in June 2016, where delayed VBIEDs hit first responders as they arrived at the scene after the initial explosion.38 Al-Shabaab has even refined IED tactics to overcome specific AMISOM and Somali National Army (SNA) countermeasures. In Merca, for example, al-Shabaab set up a double IED trap: a small motorcycle alarm IED served as bait to lure in a bomb unit, while a second, much larger IED lay buried deeper than usual (in order to prevent detection by bomb sniffing dogs) exactly under the spot where the bomb-recovery vehicle would park while disarming the first IED.39

The purge of foreign influence, reliance on local materiel, and sophistication in bomb deployment all point to al-Shabaab’s local IED skills—warranting concern on their own merits. Al-Shabaab’s most sophisticated attacks may indeed rely on new technologies imported from abroad, but it is nonetheless the group’s Somali operatives who establish the makeshift IED factories in abandoned industrial facilities, storage sites, and garages; conceal the bombs in false floors or as cargo in trucks and minivans; distribute IEDs without detection throughout the capital and south-central Somalia; and implement them to deadly effect.40 Responses such as isolating al-Shabaab from AQAP and other external actors and/or applying a ‘find, fix, and finish’ logic to a handful of tech-savvy bomb makers are therefore unlikely to fully resolve Somalia’s new challenge. To the extent that recent IED attacks indicate advancing internal abilities to make, move, and deploy cheap and crude but effective bombs, al-Shabaab will continue to propel Somalia’s conflict forward through its devastating IED campaign.     CTC

Daisy Muibu is a Ph.D. student at The School of Public Affairs at American University in Washington, D.C., where she focuses primarily on the Horn of Africa. She holds a master’s degree from the Department of War Studies at King’s College London. Follow @daisy_muibu

Benjamin P. Nickels is Associate Professor of Counterterrorism and Counterinsurgency at the Africa Center for Strategic Studies, where he focuses primarily on the Sahel, North Africa, and the Horn of Africa. He holds a doctorate and master’s degree from the University of Chicago. 

Substantive Notes
[a] Sahan research materials were provided to the authors in fall 2017. Sahan is a think-tank with offices in Somalia, Kenya, and the United Kingdom focused on security and development in the Horn of Africa, East Africa, and the Middle East.

[1] Hussein Mohamed, Eric Schmitt, and Mohamed Ibrahim, “Mogadishu Truck Bombings are Deadliest Attack in Decades,” New York Times, October 15, 2017.

[2] Abdirahman O. Osman, “The latest number of casualties 642 (358 dead, 228 injured, 56 missing). 122 injured ppl flown to Turkey, Sudan & Kenya,” Twitter, October 20, 2017; Jason Bourke, “Mogadishu truck bomb: 500 casualties in Somalia’s Worst Terrorist Attack,” Guardian, October 16, 2017.

[3] Bill Roggio and Caleb Weiss, “Jihadist Hit Mogadishu with Car Bombs, Suicide Assault,” Threat Matrix, A Blog of FFD’s Long War Journal, October 15, 2017.

[4] Sudarsan Raghavan, “Foreign Fighters Gain Influence in Somalia’s Islamist al-Shabab Militia,” Washington Post, June 8, 2010.

[5] Kalume Kazungu, “Shabaab bombs use explosives seized from Kenyan bases, expert says,” Daily Nation, July 1, 2017.

[6] Katherine Zimmerman, “Al Qaeda’s Strengthening in the Shadows,” American Enterprise Institute, July 13, 2017, p. 7.

[7] Ty McCormick, “U.S. Attacks Reveal Al-Shabab’s Strength, Not Weakness,” Foreign Policy, March 9, 2016.

[8] “Report of the Monitoring Group on Somalia and Eritrea Pursuant to Security Council Resolution 2244 (2015),” United Nations, October 2016, p. 39.

[9] Roland Marchal, “A tentative assessment of the Somali Harakat Al-Shabaab,” Journal of Eastern African Studies 3:3 (2009), p. 389.

[10] Rob Wise, “Al Shabaab,” Center for Strategic & International Studies, AQAM Futures Project Case Study Series: Case Study Number 2 (2011), p. 8.

[11] Stig Jarle Hansen, Al-Shabaab in Somalia: The History and Ideology of a Militant Islamist Group (New York: Oxford University Press, 2016), p. 55.

[12] “JTIC Special Report: Foreign fighters and foreign policy in the Somali jihad,” IHS Jane’s Terrorism and Insurgency Monitor, Couldson 12:1 (2012), 8; Roland Marchal, “The Rise of a Jihadi Movement in a Country at War: Harakat al-Shabaab al Mujaheddin in Somalia,” SciencesPo/CERI, March 2011, p. 16.

[13] Sudarsan Raghavan, “Foreign Fighters Gain Influence in Somalia’s Islamist al-Shabab Militia,” Washington Post, June 8, 2010.

[14] Matt Bryden, The Reinvention of Al-Shabaab: A Strategy of Choice or Necessity? (Washington, D.C.: Center for Strategic and International Studies, 2014), p. 5; “Somalia: Open Letter to Al-Shabaab Leader Reveals – ‘Yes, There Are Problems,” Hiiraan Online, May 1, 2013; Stig Jarle Hansen, “An In-Depth Look at Al-Shabaab’s Internal Divisions,” CTC Sentinel 7:2 (2014), p. 10; Rashid Nuune, “Al Qaeda, Al-Shabaab Pledge Allegiance…Again,” Somalia Report, February 9, 2012; Abdulkador Khalif, “Al-Shabaab foreign fighters flee Somalia,” Daily Nation, February 24, 2012; Ken Menkhaus, “Al-Shabaab’s Capabilities Post-Westgate,” CTC Sentinel 7:2 (2014), p. 5.

[15] Menkhaus, pp. 4-5.

[16] Andrew Byers and Tara Mooney, “Al Qaeda in the age of ISIS,” Hill, July 7, 2017.

[17] Christopher Anzalone, “The Resilience of al-Shabaab,” CTC Sentinel 9:4 (2016), p. 13.

[18] Hansen, Al-Shabaab in Somalia, p. 128.

[19] Thomas Joscelyn, “Shabaab spokesman calls on Kenyan jihadists to form an ‘army,’” FDD’s Long War Journal, May 22, 2017.

[20] Dominic Wabala, “Al Shabaab kill Kenyan fighters over spying suspicion,” Standard Media, April 02, 2017.

[21] “UNMAS: Central Mogadishu free from all known unexploded ordnance,” United Nations, April 11, 2014.

[22] Kazungu.

[23] Cyrus Ombati and David Ohitio, “KDF soldiers kill Al Shabaab leader who plotted deadly raid,” Standard Media, January 22, 2016.

[24] “Al-Shabaab attacks Kenyan army base in Somalia,” eNCA, January 27, 2017.

[25] “Feature: IEDS – An indiscriminate killer,” Defence Web, July 28, 2015; Kazungu.

[26] “Report of the Monitoring Group on Somalia and Eritrea Pursuant to Security Council Resolutions 751 (1992) and 1907 (2009),” United Nations, March 2010, pp. 50-51.

[27] Kazungu.

[28] “Feature: IEDS – An indiscriminate killer.”

[29] Christopher Harnisch, “The Terror Threat from Somalia: The Internationalization of Al Shabaab,” Critical Threats Project, American Enterprise Institute, February 12, 2010; Marchal, “The Rise of a Jihadi Movement,” p. 66.

[30] Tricia Bacon, “This is why al-Shabab won’t be going away anytime soon,” Washington Post, July 6, 2017.

[31] Kevin J. Kelley, “UN: KDF Makes money on illicit charcoal exports from Somalia,” Daily Nation, November 6, 2016; Elsa Buchanan, “UN report finds Kenya still funding al-Shabaab terror group through illegal sugar and charcoal trade,” International Business Times, November 8, 2016.

[32] “Somalia: Al-Shabaab demands ransom for the release of kidnapped aid workers,” Garowe Online, July 16, 2017.

[33] Robyn Kriel and Briana Duggan, “CNN Exclusive: Somali pirate kings are under investigation for helping ISIS and al-Shabaab,” CNN, July 10, 2017; Bacon.

[34] “Feature: IEDS – An indiscriminate killer.”

[35] Ibid.

[36] Ibid.

[37] Sahan research.

[38] Ibid.

[39] “Feature: IEDS – An indiscriminate killer;” Kazungu.

[40] Sahan research.

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