Fighting in northern Nigeria between government forces and Islamist militants is reported to have left about 50 people dead.
A Nigerian army official said soldiers Boko Haram militants had suffered heavy casualties in a lengthy gun-battle in the town of Damaturu.
The BBC reports that the group, whose name means 'Western education is forbidden', often targets security forces and state institutions
The army said the militants were armed with "sophisticated and heavy weaponry" and bombs.
Seven policemen and two soldiers died in the clashes, the police said.
Deaths were also reported after clashes in Potiskum to the west of Damaturu.
Boko Haram first came to prominence in 2009 when hundreds of its followers were killed when they attacked police stations in Maiduguri.
Its founder, Mohammed Yusuf, was arrested but died in police custody.
Boko Haram resumed its attacks - mostly in Maiduguri - a year later and has since staged deadly raids across the mostly Muslim north, as well as central areas such as Jos and Abuja.