Updated

Emergency officials say three suicide bombers set ablaze three fuel tankers in Nigeria's northeastern city of Maiduguri but killed only themselves.

Officials are blaming Boko Haram insurgents who many times have attacked Maiduguri, the birthplace of the Islamic extremist group.

Friday's attack comes days before the U.N. Security Council is scheduled to visit Maiduguri on a tour of countries in the Lake Chad Basin, which has been devastated by the Boko Haram uprising.

Spokesman Abdulkadir Ibrahim of the National Emergency Management Agency says a fire caused by Friday's explosions is under control. He says one bomber exploded beside a tanker, killing the two others and setting ablaze the other tankers.

More than 20,000 have been killed by Boko Haram over the past seven years, with 2.6 million people left homeless.