The infiltrators have at times even managed to cut the fence to sneak into India. The fence is 500 meters to two kilometres inside Indian territory.

An army official said that air surveillance is also on along the frontier.

Security has been reviewed at all sensitive areas and installation in the Kashmir Valley, police said.

Separatist groups fighting to end Indian rule over Jammu and Kashmir routinely step up attacks on security forces and government landmarks both in the run up to and during Independence Day and Republic Day.