Witnesses say that a suicide bombing at market in the northeastern city of Maiduguri has killed as many as 20 people.

The town had already been attacked in the early hours of the morning on Tuesday by the extremist Boko Haram movement.

Hours later, a man blew himself up at Gamboru cattle market, according to witnesses who spoke on condition of anonymity for fear of reprisals. One said he counted at least 20 bodies.

More than 30 people had already died in attacks over the weekend.

President Muhammadu Buhari announced on Friday that he is moving the military headquarters of the war from Abuja, the capital in central Nigeria, to Maiduguri.