A female suicide bomber blew herself up and killed at least 13 people in a cellphone market in Azare, said Bauchi state police.
No one claimed immediate responsibility for Sunday's blast, but Boko Haram, which has waged a five-year campaign to establish an Islamic state in northern Nigeria, is suspected of having carried out a wave of recent attacks. Azare is in the northeast region of Africa's largest economy and top oil producing nation.
"So far, 13 persons were confirmed dead while 65 others sustained various degrees of injuries," said Haruna Mohammed, a Bauchi state police spokesman.
"A suicide bomber came into the market as it was closing and blew herself up n the middle of all the merchants and customers," a witness told the AFP news agency.
Another witness, Shehu Aminu, told Reuters, "I got to the scene immediately after the blast. I saw about 20 people just lying in blood. One person I noticed that was moving."
Residents said the bomber entered the market accompanied by two men, one of whom they said was killed by an angry mob after the blast.
The attack came a day after the Nigerian army said it had recaptured and secure the northeastern town of Chibok, where Boko Haram rebels kidnapped more than 200 schoolgirls in April. The group had captured the town on Thursday.
The attack near Azare's stadium was the third bombing in the town in recent weeks.
At least seven people were killed on Nov. 7 by a blast outside a branch of the First Bank of Nigeria in Azare. Police said at the time that they believed a female suicide bomber was responsible for the explosion.
A suicide bomber blew himself up at a school on Nov. 10, killed 48 people in Potiskum, which is about 60 miles west of Azare.
On October 23, a bombing near an Azare bus station killed at least five people.
Al Jazeera and wire services