MAIDUGURI, Nigeria - Three blasts hit the northeastern Nigerian town of Maiduguri on Saturday in the worst attack on the city since suspected Boko Haram militants failed in a bid to seize the state capital at the end of January.

A witness heard the three explosions, all coming in a period of just over half an hour from about midday in a city of some two million people.

Maiduguri is the state capital of Borno, the heartland of 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.

A military source said bombs had caused the explosions, with the first on Baga road near a market and the second at the Monday market. The location of the third blast was not immediately known and there was no word on casualties.

"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, said.

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.