Al-Shabaab has claimed responsibility for the deadly suicide bombing at the gate of a well-known hotel in Mogadishu, Somalia on Sunday.
At least 15 people were killed.
The Somalia-based militant group was designated as a foreign terrorist orgaization by the United States in March 2008.
It has been blamed for a series of attacks in Somalia and surrounding nations.
A university attack in Kenya this April is among the latest, killing 148 people.
According to the Council on Foreign Relations, the group wants to turn Somalia into a fundamentalist Islamic state.
The size of the group is not clear.
The group is also al-Qaida-linked.