At least 23 people were killed and more than 100 injured in three near-simultaneous explosions in Maiduguri, police said.
The blasts struck busy locations across the capital of Borno State on Monday evening. Police spokesperson Nahum Kenneth Daso said the attacks were likely carried out by suicide bombers.
The targets included a crowded market, the University of Maiduguri Teaching Hospital, and a busy overpass in the city centre. No group had claimed responsibility as of Tuesday morning.
The region has endured more than 15 years of violence linked to Boko Haram, which frequently carries out attacks in the northeast. Maiduguri has long been considered one of the group’s strongholds.
A rival faction, Islamic State West Africa Province, is also active in the region and continues to battle government forces.
Both groups aim to impose a strict interpretation of Islam in Nigeria, Africa’s most populous nation, home to about 220 million people.
According to aid organizations, more than 40,000 people have been killed and around 2 million displaced since the insurgency began in 2009.