At least 15 people, including a local police chief, have been killed in a shoot-out between security forces and members of a radical Islamist sect in north-eastern Nigeria, authorities have said.
The shootings took place in the city of Potiskum, which has increasingly become the scene of violent attacks by the sect known as Boko Haram.
Army spokesman Lieutenant Eli Lazarus said the attack began late on Sunday night and went on for hours after suspected sect members bombed a local police station and attacked a bank branch.
Lt Lazarus said the dead included a police chief and 15 suspected Boko Haram members.
Civilians have been killed in such shoot-outs before and Nigeria's military routinely plays down such casualties.
The identity of those who died could not be independently verified and Lt Lazarus offered no details about how he knew the dead belonged to the sect.
The motive for the attack was unclear, though analysts and local security officials believe Boko Haram has funded some of its attacks through bank robberies in which sect members blow open bank buildings to steal the money inside.
Boko Haram, whose name means "western education is sacrilege" in the Hausa language of Nigeria's Muslim north, is waging an increasingly bloody campaign of guerrilla attacks against the nation's weak central government.
The sect says it wants Nigeria to enact strict Shariah law and release its imprisoned members. Despite a heavy military and police presence, the sect has been able to launch frequent attacks.
More than 770 people have been killed in Boko Haram attacks so far this year, according to an Associated Press count, making 2012 the worst year of violence attributed to the group.