The attack is the deadliest on a military base in the disputed Himalayan region in recent years, the army said.

Four rebels were killed as the soldiers returned gunfire to the attackers in the surprise assault before dawn on the base close to the highly militarized Line of Control dividing Kashmir between India and Pakistan.

Loud explosions were heard and several barracks caught fire in the initial hours of the attack.

It wasn't immediately clear if the four dead rebels were the only attackers.

Afterward military helicopters hovered over the base as the army conducted what they described as "mopping up" operations.

The casualties were high because a large number of soldiers were turning over the base to new units and were stationed in tents and temporary shelters that caught fire in the attack, the army said in a statement.

The base in the town of Uri, west of Kashmir's main city of Srinagar, houses the Indian army's brigade headquarters in the region along the de facto border.

Several wounded soldiers have been airlifted to the army's main hospital in Srinagar.

The attack came as Kashmir is in middle of the largest anti-India protests in recent years since the killing on 8 July of a popular rebel commander by Indian troops.

Protesters throwing rocks have clashed with troops firing live ammunition and shotgun pellets, and more than 80 people have been killed.

Kashmir is claimed by both India and Pakistan in its entirety, and most people in the Indian-administered portion favour independence or a merger with Pakistan.

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