Islamist terrorists murdered nothing less than 25 soldiers and a number of civilians in an ambuscade in northeast Nigeria, two security sources reported.

Militants opened fire as the troops were escorting a group of evacuees from a village in Borno state, where Boko Haram and other militants have been fighting for a decade.

“They ambushed and surrounded the vehicles of both the soldiers and the civilians and opened fire on them,” said one of the sources, part of a vigilante group that fights alongside the military against the insurgencies.

“They exchanged fire for some minutes before the Boko Haram militants overpowered the soldiers.”

Nigeria's government has said the Boko Haram insurgency, and the rival Islamic State West Africa Province group, are on their last legs.

But maintained efforts in getting rid of the militants have failed and the military continues to suffer heavy losses.

The war has killed more than 30,000 people and displaced millions more.

The troops were evacuating villages in the region on Saturday to carry out operations against Boko Haram, the sources said. One said the civilian convoy had as many as 50 vehicles.

This is the second deadly assault on the troops this week.

Earlier on Wednesday, Islamic State's West Africa branch claimed responsibility for a raid in Nigeria in which it said 20 soldiers had been murdered, and released a video purporting to show the murder of nine other Nigerian troops.