On 27 March 2015, Al-Shabaab militants launched an attack on the Makka al-Mukarama hotel in Mogadishu, Somalia. The siege ended a few hours later on 28 March, after a special forces unit of the Somali Armed Forces stormed the premises, recaptured it, and killed all five of the attackers. According to the Ministry of Information, around 20 people died during the standoff, including the perpetrators, security forces, hotel security guards and some civilians, with around 28 wounded. The special forces also rescued more than 50 hotel guests. President of Somalia Hassan Sheikh Mohamud ordered an investigation into the attack, and the Ministry of Information announced that the federal government was slated to pass new laws to curb illicit firearms. On 8 May, the Makka al-Mukarama hotel officially reopened after having undergone renovations.

Harakat al-Shabaab al-Mujahideen (HSM; Arabic: حركة الشباب المجاهدين, lit. 'Ḥarakat ash-Shabāb al-Mujāhidīn', Somali: Xarakada Mujaahidiinta Alshabaab, lit. 'Mujahideen Youth Movement' or 'Movement of Striving Youth'), more commonly known as al-Shabaab, is a Somalia-based terrorist jihadist fundamentalist group active in East Africa and Yemen. The group describes itself as waging jihad against "enemies of Islam" and is engaged in combat against the Federal Government of Somalia and the African Union Mission to Somalia (AMISOM). The group has been suspected of having links with al-Qaeda in Islamic Maghreb and Boko Haram. Due to its Wahhabi roots, al-Shabaab is hostile to Sufi traditions and has often clashed with the Somali Sufi militia Ahlu Sunna Waljama'a. Al-Shabaab’s leaders and commanders are mainly from the Hawiye clan, which is one of the largest clans in Somalia. It has attracted some members from Western countries, including Briton Samantha Lewthwaite and American Abu Mansoor Al-Amriki.

Formed in the mid-2000s, al-Shabaab came to prominence in the 2006–2009 Somalia War. In early August 2011, the Transitional Federal Government under Sharif Sheikh Ahmed and its AMISOM allies managed to capture all of Mogadishu from the al-Shabaab militants. In 2012, al-Shabaab pledged allegiance to the militant Islamist organization al-Qaeda and its leader Ayman al-Zawahiri. In February 2012, some of the group's leaders quarreled with al-Qaeda over the union and quickly lost ground. Al-Shabaab's troop strength was estimated at 7,000–9,000 militants in 2014. In August 2014, the Somali-government-led Operation Indian Ocean was launched to clean up the remaining insurgent-held pockets in the countryside. On 1 September 2014, a U.S. drone strike carried out as part of the operation killed al-Shabaab leader Ahmed Abdi Godane, also known as Mukhtar Abu Zubair. U.S. authorities hailed the raid as a major symbolic and operational loss for al-Shabaab, and the Somali government offered a 45-day amnesty to all moderate members of the militant group.As of 2015, the group had retreated from the major cities, however al-Shabaab still controlled large parts of the rural areas. The group remains strong and active and is responsible for many terrorist attacks with high death tolls, including the September 2013 Westgate shopping mall attack in Kenya, the 14 October 2017 Mogadishu bombings and the December 2019 Mogadishu bombing. Al-Shabaab has been designated as a terrorist organization by Australia, Canada, Malaysia, the United Arab Emirates, the United Kingdom and the United States. As of June 2012, the U.S. State Department had open bounties on several of the group's senior commanders. As of 2020, al-Shabaab had an estimated 5,000-10,000 fighters across Somalia.