The blasts occurred at a makeshift market near the Terminus bus station, which had been set up after a twin car bomb attack in May that left at least 118 people dead.
“I saw a flash of light and heard a loud boom. Afterwards there was debris everywhere and mutilated bodies,” witness Tanko Mohammed said
Mohammed Abdulsalam, coordinator for the National Emergency Management Agency (NEMA) in the city, said the scene of the attack was a densely populated area.
“The bodies recovered so far are 31 but rescue workers are at the scene and the figures may change,” added Pam Ayuba, spokesman for Governor Jonah Jang.
The city has been targeted by Boko Haram Islamists in the past but is also a hotbed of ethnic and sectarian tensions that frequently boil over into deadly violence.