MANILA, Dec. 26 (Xinhua) -- Philippine troops have killed at least 10 extremist rebels in airstrikes in southern Philippines' Maguindanao province, the military said on Tuesday.

The troops launched the airstrikes around 10:00 p.m. local time on Monday after an undetermined number of Bangsamoro Islamic Freedom Fighters (BIFF) attacked an army post in Maitumaig village in Datu Unsay town, the military said.

Two gunship helicopters were sent to the area and bombed the rebel positions for four hours until 2:00 a.m. Tuesday, the military said.

Several rebels were also injured in the military offensive, the military said.

The military said a clearing operation is now underway after successfully repelling the rebels.

The fresh attack took place while Mindanao is under the martial rule. Philippine President Rodrigo Duterte has imposed the martial law in entire Mindanao to totally crush antigovernment rebels in the region.