Source: BBC News
Some 480 Nigerian soldiers have crossed into Cameroon following fierce fighting with Boko Haram militants.
Reports claimed that the troops had joined thousands of citizens fleeing the fighting, but Nigeria said they were conducting a “tactical maneuver”.
Clashes are said to be continuing in the border town of Gamboru Ngala.
Boko Haram on Sunday released a video claiming that it had established an Islamic state in the towns and villages it controls in north-eastern Nigeria.
The group’s five-year insurgency has intensified in recent months despite the deployment of thousands of extra troops to the worst-affected areas.
Last week, a group of soldiers refused to follow orders to go and fight Boko Haram, saying the militants were better equipped.
Insurgents also seized one of Nigeria’s two main police training academies, which is near the town of Gwoza, captured earlier this month.
The Nigerian soldiers were accommodated in the Cameroonian town of Maroua, about 80km (50 miles) from the Nigerian border, Cameroon army spokesman Lt Col Didier Badjek told the BBC.
The Nigerian defence ministry said in a statement that the soldiers found themselves “charging through the borders in a tactical maneuver” after a sustained battle.
The statement said it was standard practice for them to hand over their weapons and the soldiers are now returning home.
Thousands of civilians are also said to have fled across the border.
Cameroon has officially closed its 1,600 km border with Nigeria to help contain the spread of the deadly Ebola virus.
But correspondents say this is impossible to enforce in remote areas near the fighting.