Three blasts struck a mosque and the area near the building in Maiduguri, Borno State, a military spokesman has said.
A hospital source, speaking on condition of anonymity, said at least eight dead bodies had been recovered from the area, with many more feared dead, and around 50 injured people had been taken to hospital for treatment.
There was no immediate claim of responsibility for the explosions on the edge of the city centre but they bore the hallmarks of the Boko Haram sect.
Maiduguri is the birthplace of the jihadist sect which has waged a six-year insurgency in its bid to set up a state in the northeast of Nigeria adhering to strict Islamic laws.
“There were three improvised explosive devices explosions at Gomari and Ajilari general area in Maiduguri at about 7:21pm [1821 GMT],” the military spokesman, Col. Sani Usman, told Reuters.
“Although details are not clear, it is important to note the attacks signify high level of desperation on the part of the Boko Haram terrorists,” he added.
Bubakar Aliyu, a farmer who had just finished praying at a smaller mosque, said, “I heard the first blast from the main mosque. Another exploded at a cluster of shops. I ran back to home and as I approached my house I heard another blast.”