At least 50 people have been killed and dozens of others injured in two explosions in northeastern Nigeria’s biggest city, witnesses said yesterday.

The first blast happened when a suicide bomber in a tricycle taxi blew himself up outside a fish market in Maiduguri, killing at least 10 people.

“I saw many dead bodies lying on the ground, many dead, and several others badly injured,” said fish seller Idi Idrisa.

The final death toll has not yet been confirmed but a security officer said the explosion at Baga fish market was massive and he counted at least 10 bodies.

A second explosion rocked the area about an hour later. It happened in the Post Office shopping area, close to the fish market where the first bomb went off, according to witness Baban Musa, who said there were many casualties.

No-one immediately claimed responsibility for the attacks but they bear all the hallmarks of the Boko Haram Islamic extremist group.

It has increased suicide bombings and village attacks recently as forces from Nigeria and Chad have driven the insurgents from a score of towns along Nigeria’s border with Cameroon.

Boko Haram has alsoattacked villages in Cameroon and Niger as Nigeria’s neighbours are forming a multinational force to confront the spreading Islamic uprising.

Chad’s President Idris Deby said this week that his forces know the whereabouts of Boko Haram leader Abubakar Shekau and warned him to surrender or face certain death.

Boko Haram fighters are massing at their headquarters in the northeastern town of Gwoza, in apparent preparation for a showdown with multinational forces, according to witnesses who escaped from the town.