A look at some terror attacks by the Islamic extremist group Al-Shabab that preceded Thursday's deadly assault on a college in northeast Kenya:

Attack on Mogadishu hotel

March 27-28, 2015: Militants carried out a deadly siege on the Maka Al-Mukarramah Hotel in Somalia's capital, Mogadishu. At least 24 people, including six attackers, were killed. That attack lasted more than 12 hours as Somalia's security forces tried to dislodge gunmen who had taken control of parts of the hotel.

Attack on Mogadishu hotel

Feb. 20, 2015: Twenty-five people were killed and 40 wounded in suicide attacks at the Central Hotel in Mogadishu. Government officials were meeting at the hotel at the time, and Mogadishu's deputy mayor and two legislators were among the dead.

Attack on quarry workers in Kenya

Dec. 2, 2014: Gunmen roused sleeping quarry workers in the dead of night in northern Kenya. After singling out the non-Muslims by asking them to recite the Islamic creed, the attackers killed 36 of them -- most with a gunshot to the back of the head.

Bus attack in Kenya

Nov. 22, 2014: Gunmen attacked a bus in northern Kenya at dawn, singling out and killing 28 passengers who could not recite an Islamic creed and were assumed to be non-Muslims.

Kenya mall attack

Sept. 21, 2013: Gunmen used grenades and assault rifles to attack an upscale mall in Kenya's capital, Nairobi, killing at least 67 people.

Terror attack in Kampala

July 11, 2010: Militants detonated near-simultaneous blasts in Uganda's capital, Kampala, at sites where crowds were watching the World Cup soccer final on large TV screens. About 76 people were killed. Al-Shabab said the attacks were in retaliation for Uganda's decision to send troops to Somalia to fight the extremist insurgents.