In an escalation of tensions, India and Pakistani troops traded heavy gunfire and mortars in Kashmir, killing at least four civilians and injuring 23 others in the disputed Himalayan region, officials said.

Police Inspector-General Danish Rana said three civilians were killed after their car was hit by a shell fired by Pakistani troops in the Balakote sector of the divided region. The dead included a village headman, ABC News reported on Saturday.

Rana said at least 20 civilians were wounded in the fighting at different places in the region and that at least six of them were being airlifted to neighboring Jammu city for treatment.

Each side blamed the other for the violence.

The two nuclear-armed archrivals have a history of uneasy relations and regularly exchange fire over the highly militarized Line of Control, the latest coming as India celebrated Independence Day on Saturday and Pakistan observed it a day earlier.

Kashmir is divided between India and Pakistan but claimed in its entirety by both.

The two countries have fought two of their three wars over their competing claims to Kashmir, though a 2003 cease-fire has largely held despite small but regular firefights.