Extremists detonated three explosive devices in Maiduguri, the capital of Borno state, in Nigeria’s north-east.
Details on casualties were not readily available, said military spokesman Col. Sani Kukasheka Usman.
No group has claimed responsibility for the attack, but the initial suspicion has fallen on the Islamic extremist group Boko Haram, which has resorted to hit-and-run tactics after the Nigerian military recaptured territory once held by the militants.
Col Usman said the attacks signify the increasing desperation of Boko Haram.
At least 20,000 people have been killed in Boko Haram’s six-year-old uprising which has displaced 2.1 million people across three countries.
More than 1,000 people have been killed by Boko Haram violence since President Muhammadu Buhari was elected in March with a pledge to wipe out the extremists.
Earlier this year, troops from Chad and Nigeria drove the extremists out of some 25 towns held for months in what had been declared an Islamic caliphate.
The insurgents in March pledged allegiance to the Islamic State group.