At least five people have been killed in a bomb blast at a police beer garden in the troubled northeastern Nigerian city of Maiduguri, a military source and a witness said.

Sunday evening's blast took place in the middle of a 'mammy market' near the police barracks in the Wulari area of the city.

Mammy markets are open-air pubs and eateries found around police or military barracks and are open to both security personnel and civilians.

Jack Nwachukwu Nwaogbo, a major-general in the Nigerian army, said the explosion killed at least five people and wounded 10.

Umar Kaulaha, a resident in the area said he had heard a "loud bang followed by dark clouds of smoke from the beer garden".

Maj-Gen Nwaogbo said three fighters from the Boko Haram group also shot and killed four people in Maiduguri late on Saturday. Nwaogbo said a fifth person was shot dead on Sunday.

Boko Haram claimed responsibility, in an unverified statement, for a June 16 bombing in Abuja. A separate blast killed 25 people in Maiduguri on June 27.

The group was behind a series of killings which have targeted police officers, soldiers, politicians and clerics in Nigeria's north over the last year - including attacks on beer parlours. They have also attacked churches and engineered a massive prison break.

The group wants strict Shariah or Islamic law implemented across the region.

Source: Agencies