CAIRO - Egypt’s military launched air strikes against militant targets in the Sinai Peninsula on Saturday, the army said, after the Islamic State group killed 12 soldiers at a checkpoint.

The northern Sinai is a stronghold of the Sunni extremists, who have killed hundreds of soldiers and police since the military overthrew Islamist president Mohamed Morsi in 2013. Friday’s attack saw mortar rounds and rockets fired at an army post west of El-Arish, the provincial capital of North Sinai, according to officials.

The military said in a televised statement that its aircraft had taken off at dawn on Saturday for a reconnaissance and bombing mission that lasted several hours and was still ongoing. It said the strikes targeted hideouts of armed extremists involved in Friday’s assault, adding that a number of the militants were killed and weapons destroyed.

The military has poured troops into the peninsula in recent years to battle the insurgency. IS has also targeted foreigners in Egypt and claimed last year’s bombing of a Russian airliner carrying tourists home from a Sinai resort. All 224 people on board were killed.