Multiple blasts in the Nigerian city of Maiduguri killed more than 50 people on Saturday and injured scores more, according to local officials.
The explosions struck two crowded markets and a bus station, officials said.
Locals told the BBC that suicide bombers were to blame for the attacks.
"Reports from the three locations indicate that 58 are dead, while 139 persons were injured," Clement Adoda, police commissioner of the northeast Borno state, told Agence France-Presse.
Many women and children were reported among the dead.
"The bomb was devastating because it occurred at a crowded area," Jamuna Jarmi, a grocery seller told AFP.
Maiduguri has long been the focus of fighting between Nigeria's military and extremist fighters from Boko Haram, who are seeking to establish an Islamic state in the country's northeast.
Chad's military has also claimed to have killed scores of Boko Haram fighters in recent weeks, as part of a military effort with the governments of Cameroon and Niger.