Two blasts ripped through the Damboa government area in Borno state on Saturday evening targeting people returning from celebrating the Eid al-Fitr holiday.
Following the suicide bombings, the attackers fired rocket-propelled grenades into the crowds that had gathered at the scene of the blasts, driving the number of casualties higher.
"There were two suicide attacks and rocket-propelled grenade explosions in Damboa last night which killed 31 people and left several others injured," Babakura Kola, from the Civilian Joint Task Force, a militia assisting the military with security, told AFP news agency on Sunday.
There was no immediate claim of responsibility but the attack bore all the hallmarks of Boko Haram, a group waging an armed campaign in northeast Nigeria for nearly a decade.
The blasts on Saturday occurred in the Shuwari and Abachari districts of the local government area, which is about 90km from state capital Maiduguri.
"It has destroyed our houses. We have also counted 31 innocent people including children and elderly killed in the attack," said local resident Modu Usman, son of a community leader, according to the Reuters news agency.
Boko Haram roughly translates to "Western education is forbidden".
More than 20,000 people have been killed and over two million have been forced to flee their homes since 2009, when the group launched its campaign which has seen the regular deployment suicide bombers in mosques, markets and camps housing displaced people.
Nigerian President Muhammadu Buhari said earlier this year that the era of Boko Haram violence "is gradually drawing to end".
However, the group continues to launch attacks in the country's northeast.