Harakat al-Shabaab al-Mujahideen (HSM) (Arabic: حركة الشباب المجاهدين; Ḥarakat ash-Shabāb al-Mujāhidīn, Somali: Xarakada Mujaahidiinta Alshabaab, "Mujahideen Youth Movement" or "Movement of Striving Youth"), more commonly known as al-Shabaab or al-Shabab (Arabic: الشباب), meaning "The Youth", or "The Youngsters", is a jihadist group based in Somalia. In 2012, it joined the militant Islamist organization al-Qaeda as a cell. As of 2013, the group retreated from the major cities, but imposed strict forms of sharia law in some rural regions. Al-Shabab's troop strength as of 2013 was estimated at 4,000 to 6,000 militants. In February 2012, the group's leaders quarreled with Al-Qaeda over the union, and quickly lost ground.
The group is an off-shoot of the Islamic Courts Union (ICU), which splintered into several smaller factions after its defeat in 2006 by the Somali Transitional Federal Government (TFG) and the TFG's Ethiopian military allies. Al-Shabab describes itself as waging jihad against "enemies of Islam", and is engaged in combat against the TFG and the African Union Mission to Somalia (AMISOM). Alleging ulterior motives on the part of foreign organizations, group members also reportedly intimidated, kidnapped and killed aid workers, leading to a suspension of humanitarian operations and an exodus of relief agents. Al-Shabab was designated a terrorist organization by several Western governments and security services. As of June 2012, the United States State Department had opened bounties on several of the group's senior commanders.
In early August 2011, the TFG's troops and their AMISOM allies reportedly managed to capture all of Mogadishu from the Al-Shabab militants. An ideological rift within the group's leadership also emerged in response to pressure from the recent drought and the assassination of top officials in the organization. Al Shabab is hostile to Sufi traditions and has often clashed with the militant group Ahlu Sunna Waljama'a. The group has also been suspected of having links with Al-Qaeda in Islamic Maghreb and Boko Haram. The group has attracted some members from western countries, notably Samantha Lewthwaite and Abu Mansoor al-Amriki.
Al-Shabab was also accused of being responsible for the deaths of tens of thousands of elephants every year for their ivory, and for killing rangers hired to protect them. The proceeds from the ivory trade allegedly supply Al-Shabab with income with which to carry out their operations. At the same time, the group also has some social support during its time in administration within Somalia as it partook in some reforms.