Islamist group based in Somalia. Singular, not plural.
Fully, Harakat al-Shabaab al-Mujahideen, “Movement of Striving Youth”; al-shabaab means “the youth” in Arabic.
Linked to other groups throughout Africa, specifically Al-Qaeda in Islamic Maghreb and Boko Haram; also has links with al-Qaeda. In October 2015, some members of al-Shabaab pledged allegiance to the Islamic State; in December, the group ordered those members to leave.