They say they believe the attack, which occurred in a beer garden, was carried out by the Islamic sect Boko Haram.

The group believes Muslims should withdraw from Western society.

It has claimed a number of bombings in north-eastern Nigeria, as well as an attack on police headquarters in the capital Abuja earlier this month.

Two men on motorcycles attacked a packed beer garden late on June 26, officials said.

"The attackers believed to be Boko Haram members threw bombs and fired indiscriminate gun shots on a packed tavern at Dala Kabompi neighbourhood, killing at least 25 people and seriously injuring around 30 others," a police officer said.