Nigerian troops have killed several militants of the Islamic State West Africa Province(ISWAP) in an encounter with the extremist group in Nigeria’s northeastern state of Borno on Saturday, the army said on Sunday.

A senior officer of the army and three soldiers were also killed in the Saturday gunfight in the Askira Uba local government area of Borno, said Onyema Nwachukwu, a spokesman for the army, in a statement reaching Xinhua on Sunday.

The troops, supported by fighter jets of the air force, killed several militants and destroyed nine gun trucks and other equipment of the militants during the encounter, said Nwachukwu.

“The deceased officer and the soldiers exhibited a rare display of gallantry, as they provided reinforcement in a counter-offensive against the terrorists and successfully defended the location,” he said, adding the troops continued in the ferocious counter-offensive and hot pursuit to eliminate the remnant of the fleeing terrorists.

In a statement mourning the deceased officer and soldiers, Nigerian President Muhammadu Buhari described their loss in the gunfight as “devastating”.

“Nigeria has lost brave soldiers. I salute their courage. May their souls rest in peace,” Buhari said.

ISWAP has been collaborating with its sister group Boko Haram to establish an Islamist state in northeast Nigeria. The terror groups have also extended their attacks to other countries in the Lake Chad Basin.