A riot police training academy near Gwoza, Borno State has been overrun by Boko Haram militants.
A witness told the British Broadcasting Corporation that shots were heard after the militants arrived in three Armoured Personnel Carriers and on dozens of motorcycles.
The BBC said in its report on Thursday that a police spokesman confirmed the attack. It added that a senior security source said it had not been possible to communicate with the academy, known as Liman Kara Police College, since Wednesday.
He said that police recruits were seen running from the college after the attack began at dawn on Wednesday.
The resident however explained that he was unable to confirm if there were casualties as he had joined other residents and fled the town to nearby hills.
A security official who did not want to be named told the BBC Hausa service that the militants had “entered the school” but said he could not confirm if they were in control.
Another resident, Kaka Modu, said some fleeing vigilance group members told him on the telephone that the community was also overran by the militants.
Modu, who added that some people were killed, said the insurgents launched the offensive on the college on Tuesday before finally seizing it on Wednesday.
He said, “The terrorists who engaged military troops with sophisticated weapons succeeded in chasing away security personnel undergoing training at the camp and took over by hoisting their flags yesterday(Wednesday) at the college. This was after the security operatives in the c college ran away.”
A similar attack on the college which is about 15 kilometres from Gwoza was repelled by officers undergoing training there two weeks ago.
The institution is one of only two riot police training colleges in Nigeria.
An online news agency, Sahara Reporters, was quoted by the BBC as reporting that several hundred militants were involved in the raid on the college which had about 290 police trainees at the time of the attack.
Thousands have been killed across the North-East since Boko Haram launched its violent campaign for an Islamic state in 2009.
When contacted on Thursday, the new Force Public Relations Officer, Emmanuel Ojukwu, said he had no information on the attack on the college.
“I don’t have any information on the attack for now,” he said over the telephone.
The sect has stepped up its attacks after being pushed out of its bases in Maiduguri and have been targeting towns and villages in deadly raids.
In recent weeks, the militants have been moving from their rural camps and taking over substantial towns,the BBC reported.
The group has been in control of Gwoza, a town of about 50,000 people , since the beginning of this month.
It apparently retreated about 100km (62 miles) to Gwoza after losing control of Damboa also in Borno State.
But attempts by the security forces to retake Gwoza have failed – and a group of about 40 soldiers is refusing to fight the insurgents.