Following is a timeline of religious and ethnic violence in Nigeria over the last 10 years:
2000 - Thousands killed in northern Nigeria as non-Muslims opposed to the introduction of sharia (Islamic law) fight Muslims who demand its implementation in state of Kaduna.
September 2001 - Christian-Muslim violence flares after Muslim prayers in Jos, with churches and mosques set on fire. At least 1,000 people are killed, according to September 2002 report by a panel set up by Plateau state government.
November 2002 - Nigeria abandons Miss World contest in Abuja. Decision follows death of at least 216 people in rioting in Kaduna, 200 km (125 miles) northwest of Jos, after newspaper article suggests Prophet Mohammad would probably have married one of the Miss World beauty queens if he were alive today.
November 2008 - Clashes between Muslim and Christian gangs triggered by disputed local government election kill at least 700 people in Jos, according to U.S.-based Human Rights Watch.
January 2010 - Hundreds are reported killed after clashes between Muslim and Christian gangs in Jos, most by gunfire. Police estimate death toll at 326, although some community leaders put the figure at more than 400.
March 2010 - Hundreds of people are killed in clashes between Islamic pastoralists and Christian villagers in the mostly Christian villages of Dogo Nahawa, Zot and Ratsat just south of Jos. Plateau State Commissioner for Information, Gregory Yenlong, said more than 300 people had died.
December 2010 - At least 80 people are killed in December 24 bombings as well as in clashes two days later between Muslim and Christian youths in Jos.
January 2011 - Human Rights Watch says more than 200 people killed in violence over preceding month, with many hacked to death or burned alive in attacks on villages, and reprisal killings in Plateau state.
August-September 2011 - At least 70 people killed in clashes in central Plateau state since beginning of August. Cycle of violence started when Christian youths attacked Muslims as they gathered to celebrate end of Ramadan in Jos.
November 2011 - At least 65 people killed in northeast city of Damaturu when Islamist insurgents bomb churches, mosques and police stations. Boko Haram militant sect claims responsibility.