Lagos - Nigeria has seen an upsurge in violence since April linked to the Islamist extremist group Boko Haram, which was accused Thursday of kidnapping at least 185 people in the volatile northeast of the country.
The insurgency has left more than 13,000 dead and 1.5 million displaced people since 2009. Here is a list of incidents since April:
- April 14: 276 young girls are seized from their school by Boko Haram gunmen in Chibok, a remote corner of Borno state in northeast Nigeria. Fifty-seven of the girls manage to flee, while 219 are still being held.
- April 14: At least 75 people die in a bomb blast in a packed bus station on the outskirts of Nigeria's capital Abuja -- the deadliest attack yet to strike the city. Boko Haram claims responsibility.
- May 5: Boko Haram gunmen raze the town of Gamboru Ngala in Borno state, killing at least 300 people, according to local sources.
Also read: Lawyer defends acts of Nigeria soldiers sentenced to death
- May 20: Twin car bombings in the central Nigerian city of Jos, blamed on Boko Haram, kill at least 118 and bring entire buildings down.
- June 3: Heavily armed gunmen raid four northeastern villages in Borno state, with local leaders putting the death toll as high as 400-500.
- July 23: Two blasts rock northern Kaduna city killing at least 42. A local official says former military ruler turned opposition figurehead Muhammadu Buhari was the target of the second attack but was unhurt.
- August 24: Boko Haram leader Abubakar Shekau claims he has made the town of Gwoza in Borno state part of an Islamic caliphate. On July 13, he had proclaimed support for the Islamic State group that controls part of Syria and Iraq.
- October 18: Around 60 women and young girls are abducted around Chibok, according to witnesses. On October 25-26, 30 adolescents are kidnapped in the village of Mafa in Borno state.
- October 31: Shekau says the 219 abducted schoolgirls have been converted to Islam and married off, ruling out talks with the authorities on a ceasefire.
- November 9: Shekau says that he has created a caliphate in the more than 20 northeastern towns conquered by the insurgents.
- November 10: A suicide attack kills at least 58 people at a boys school in Potiskum in Yobe state.
- November 28: Two suicide bombers blow themselves up and gunmen open fire during weekly prayers at the mosque of the Emir of Kano, one of Nigeria's top Islamic leaders. At least 120 people are killed and 270 others wounded.
- December 1: More than 150 people, including 44 police and security troops, die in a Boko Haram raid on the northeast Nigerian city of Damaturu.
- December 18: Local militia chiefs say Boko Haram kidnapped on December 14 at least 185 people from Gumsuri.
The mass abduction was part of an attack that also killed 32 people.