Nigeria;s militant Islamist group Boko Haram has captured the town of Banki, which borders Cameroon, according to a BBC report.

The military has not yet commented on the latest town to reportedly fall to the insurgents in recent weeks.

Fears have been raised that their main target is Maiduguri, the capital of north-eastern Borno state.

Residents from Banki say that government troops abandoned their posts as the militants advanced on the small border town on Tuesday.

Most of the people remaining in the town were women and children, as many of the men had fled, one man who was hiding in the bush nearby told the BBC Hausa service.

The militants have not harmed anyone in the town, residents said.

The capture of Banki gives Boko Haram leverage as it tries to secure territory beyond north-eastern Nigeria, says BBC Nigeria analyst Jimeh Saleh.

“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,” the Nigeria Security Network (NSN) said in a special report released on Tuesday entitled ‘North-East Nigeria On The Brink’.

“If Maiduguri falls, it will be a symbolic and strategic victory unparalleled so far in the conflict,” it said.

“A successful attack could be followed by a takeover of the whole of Borno State and possibly parts of Adamawa, Yobe, and neighbouring Cameroon.”

•Photo shows Boko Haram fighters on the advance.