Counterterrorism police said in a statement they had stormed a hideout in the southwestern city of Quetta on Saturday and killed six militants, but "around four to five managed to escape".

A senior police official speaking on condition of anonymity told AFP that "teams are now raiding different areas to arrest those who escaped".

Among the dead was Asghar Sumalani, a junior commander in the regional chapter of Islamic State-Khorasan (IS-K). He had a two million rupee ($11,400) bounty on his head.

Pakistani officials have long played down the presence of IS-K in their country.

But the group has claimed responsibility for numerous attacks, including the slaying of 11 miners from the minority Shiite Hazara community last year.

Some of the miners were beheaded after being kidnapped from a remote coal mine in the mountainous Machh area, 60 kilometres (37 miles) southeast of Quetta.