Nigerian troops on Sunday overpowered a group of Boko Haram fighters, killing at least three, following a gunfight in the northeastern state of Borno.

According to a statement by the army on Twitter, the troops of 21 Brigade were on a clearance patrol, when they were ambushed by the terrorists along Maiduguri-Bama axis of the state.

"There was a serious exchange of gunfire,” the statement said.

Photos posted on Twitter showed at least three Boko Haram fighters killed, with arms and ammunition recovered.

The statement added that troops are still combing the area in search of some Boko Haram fighters who escaped with gunshot wounds.

Last Wednesday night, many Boko Haram fighters were killed in the northeastern town of Damasak, also in Borno, following a gunfight with troops.

Boko Haram has been trying since 2009 to establish an Islamist state in northeastern Nigeria, in the process killing some 20,000 people and displacing millions of others.

The group in the Lake Chad Basin has posed enormous security, humanitarian and governance challenges, according to the United Nations.

Four countries caught up in the insurgency are Cameroon, Chad, Niger, and Nigeria. The UN said Boko Haram has displaced nearly 2.4 million people in the Lake Chad sub-region.

Xinhua