A rescue worker who asked not to be identified said his colleagues had counted 12 dead bodies and that around 25 people had been wounded by the blast. A hospital spokesman said 10 corpses had been brought in, four of them women.

The explosion hit the Mamy market in the barracks on the edge of the city of Bauchi at around 8 p.m. (3 p.m. ET), police commissioner Muhammed Indabawa said. He said it was not clear who was responsible and that no arrests had yet been made.

"It was a very strong and powerful explosion," said Yushua Shuaib, spokesman for the National Emergency Management Agency (NEMA), adding members of the agency were evacuating the wounded. He declined to comment on the death toll.

Military barracks in Nigeria sometimes contain small market areas where traders are allowed to sell food, drink and other goods to both soldiers and members of the public. Mamy market is a popular evening drinking spot for Bauchi residents.

A second, smaller explosion hit a beer parlour in Zuba on the outskirts of the capital Abuja, although the cause was unknown and there were only three minor injuries, Shuaib said.

The blasts underline the challenges Jonathan faces uniting Africa's most populous nation after elections last month which, while deemed the most credible in decades, also exposed the country's religious and ethnic fault lines.

Hundreds of people were killed in northern towns last month in riots and reprisal killings after Jonathan, a Christian from the south, was declared winner of the election, beating northern Muslim and former army ruler Muhammadu Buhari.

"We will not allow anyone to exploit differences in creed or tongue to set us one against another," Jonathan said in a speech at his inauguration ceremony.