A bomb blast which occurred, Saturday, at a busy market near a bus station, in Damaturu, the Yobe State capital, has killed at least seven people, a witness at a nearby hospital said.
At least 27 people were wounded, many critically, and ambulances continued to bring in the injured.
There was no immediate claim of responsibility for the blast, but it bore the hallmark of Islamist militant group Boko Haram, which has been fighting a six-year insurgency in a bid to establish an Islamic state in northern Nigeria.
Boko Haram took over a territory larger than Belgium last year, killing thousands of people and displacing some 1.5 million. The militants took over most of Borno state and parts of Adamawa and Yobe.
The Nigerian army has gone on the offensive recently and says Boko Haram has now been pushed into the vast Sambisa forest in eastern Borno state.