Terrorist faction Boko Haram is attempting to assure residents in villages across northern Nigeria they will not be attacked if they remain in towns under the group's control, according to AP reports.

Michael Kirshinga, a fleeing former resident of Gulak, a town in the Adamawa state attacked at the weekend, said the militants "assured us that they will not attack us".

"Some of us have fled for fear that, after subduing the soldiers, the insurgents will turn their [gun] barrels on us."

Several towns - including Duhu, Shuwa and Kirshinga - also were raided over Friday night and Saturday.

The militants also tried to seize Maiduguri, the Borno state capital, but they were ambushed by government forces in a village outside Kondudga, 40 km from Maiduguri.

Boko Haram insurgents are attacking several cities across northern Nigeria, in a bid to expand the Islamic caliphate they proclaimed in Gwoza, along the Cameroon border, last August.

More than 26,000 people fled the recently occupied Bama, where the insurgents killed dozens of civilians and clashed with government forces.

Government attempts to reassure residents that the situation is under control have done little to allay fears of further attacks.

"We are so very scared. If they are to come attacking, as has been rumoured, we doubt if they would spare us because they have to pass in front of our school before getting to the town," student Halima Muhammad said.

Boko Haram - meaning Western education is forbidden - says it is fighting against Western influence in Nigeria and trying to impose its own form of Sharia law.

The Islamic fundamentalists gained global notoriety when it abducted 220 schoolgirls in Chibok, last April, which led to fears that the victims would be used as suicide bombers.

Borno, Yobe and Adamawa, where the militants usually carry out their attacks, have been under a state of emergency since May 2013.

According to the UN, at least 1.5 million people have fled their homes in Nigeria since last year, due to the violent insurgence.