Pakistani police say two gunmen shot and killed a police officer and wounded two others in an attack on a patrol on a main road in the capital, Islamabad.

Police officer Tariq Javed says the two gunmen escaped on foot after the shooting late Friday on a busy road linking Islamabad to its twin city, Rawalpindi. He says one of the wounded officers is in critical condition.

A local affiliate of the Islamic State group claimed the attack in a statement circulated online by supporters.

But Javed says police have no indication that the group was involved.

Pakistan denies the existence of any IS affiliate on its soil, saying militants invoke the group's name to sow fear.