Witnesses say two explosions blasted a crowded marketplace in northeastern Maiduguri city, and many are feared killed and wounded in the birthplace of Nigeria's Boko Haram terrorist network.

Survivors say bloodied people are screaming for help and some people were blown apart.

Trader Mallam Samaila said it appeared to be a car bomb in a pickup truck loaded with wood. He said the second explosion caught people trying to help those injured in the first blast.

Smoke is billowing from buildings in the Bintu-Suga neighborhood of the city's Ngomari suburb.

The first attack in months in Maiduguri, capital of Borno state, follows an increasing number of ever-deadlier attacks in neighboring Yobe and Adamawa states. More than 300 people have been killed this month in attacks in the northeastern Islamic uprising.