Boko haram extremists attack Nigeria
Islamist militants have continued to capture territory in Borno state YouTube

Cameroon's military has revealed that it has killed over 100 Boko Haram fighters who attempted to cross the border from Nigeria and attack a town, according to state media.

According to Cameroon Radio Television, the Communication Ministry said that a battle ensued between the military and Boko Haram insurgents in the town of Fotocol, located across the border from Borno state, the heart of the Islamist militant group's insurgency.

No Cameroonian soldiers were killed in the fighting and the military dealt "a severe setback" to the group during the clashes, government spokesman Issa Tchiroma Bakary said in a statement.

According to the radio report, Boko Haram insurgents fired two shells on the Cameroonian town before the army retaliated with mortar and gun fire.

The Islamist militants were pegged back and forced to retreat to the border town of Gamboru Ngala following the deaths of over 100 of their men.

Boko Haram have continued to seize territory in Borno state such as the towns of Damboa, Gwoza and Bama, although the Nigerian military claims to have recaptured Bama.

Experts from the Nigeria Security Network (NSN) have warned that Boko Haram is now plotting a major offensive on the Borno state capital of Maiduguri in similar fashion to the Islamic State's capture of Mosul city.

"Unless swift action is taken, Nigeria could be facing a rapid takeover of a large area of its territory reminiscent of Isis's lightning advances in Iraq," their new report, entitled North-East Nigeria On The Brink, claimed.

Thousands of Nigerians living in Borno state have fled the group's violence into Cameroon but now the group are attacking towns in the neighbouring country.

Earlier this year, the group kidnapped more than 200 schoolgirls in the village of Chibok, bringing global attention to the west African nation's fight against terrorism.

Three states – Borno, Yobe and Adamawa – have been under a state of emergency since May last year.

According to Human Rights Watch, the militants have killed at least 2,053 people since the beginning of 2014.