UN imposes sanctions against Boko Haram

The Boko Haram, under the leadership of Abubaker Shekau, abducted more than 200 girls from school dormitories in the town of Chibok. Shekau, in a video, claimed responsibility for the kidnappings and threatened to sell the girls if his demands were not met.

Ab explosion May 18 in the northern city of Kano killed four people, including a 12-year-old girl.

More than 300 people were killed by the militants May 5 in the town of Gamboru Ngala.

A car bomb May 2 claimed at least 19 lives in Nigeria's capital Abuja.

The Boko Haram, meaning "Western education is sin", has killed thousands of people in Nigeria through a wave of bombings and assassinations since 2009, and is fighting to overthrow the government, create an Islamic state and ban Western education.