The Indian army says three of its soldiers have been killed along the highly militarized de facto border that divides the disputed region of Kashmir between India and Pakistan.

Army spokesman Col. Rajesh Kalia says the attackers on Tuesday also mutilated the body of one soldier.

He said "retribution will be heavy for this cowardly act."

Kalia did not specify if the attack was carried out by Pakistani soldiers or rebels fighting against Indian rule in the region.

In the past, the Indian army has blamed a combination of the Pakistani army's border action team and militants for carrying out operations along the Line of Control.

India and Pakistan have been trading fire in recent months in the Himalayan region, which is claimed by both.