Three explosions hit the northeastern Nigerian town of Maiduguri today on Saturday.
There was no immediate official word on casualties. A hospital source said dozens had been killed in the separate explosions and witnesses saw bodies being taken away from different blast sites.
A tricycle rider with a bomb tried to enter a fish market on the Baga road in the west of Maiduguri. The bomb exploded when the tricycle was prevented from going in, Mohammad Ajia, a trader in Baga market, said after fleeing the scene.
A second blast then hit an area known as the Monday market before a car bomb exploded by a bus station near a Department of State Security (DSS) office, according to a civilian member of a joint task force.
"Men from the anti-bomb squad came a few minutes after the blast to comb the scene, then they started evacuating victims. I saw five mangled bodies being put in vehicles," Aliyu Musa, a resident in the area near the DSS office, said.
Near the Monday market, casualties were loaded onto waiting ambulances.
"I have counted five ambulances that have evacuated victims from the scene. Soldiers are shooting in the air and warding off people at the market," Salisu Yaya, a member of a civilian task force, told Reuters from the Monday market area.
Maiduguri is the capital of Borno state, the heartland for the militant Islamist group Boko Haram which has long coveted the city as the capital of an Islamic state they want to carve out of religiously mixed Nigeria.
Suspected Boko Haram militants tried to seize the city at the end of January but were repelled in fighting that killed more than 100 people.
Boko Haram seized territory the size of Belgium last year, which Nigeria's ill-equipped army has struggled to take back, and the group gained worldwide notoriety in April when members kidnapped more than 200 schoolgirls.
President Goodluck Jonathan, who is seeking re-election on March 28, has been heavily criticized for the failure to crush the insurgents. The vote was postponed for six weeks from Feb. 14 for security reasons.
Since the delay, Chadian troops cooperating with the Nigerians have reclaimed some important towns in Borno. The army has also been able to push the militants out of some territories in neighboring Adamawa and Yobe states.
