At least four soldiers were killed in a shooting at a military base in Punjab, a border state in India early Wednesday, sources said as the army launched a search for the shooters.

An unknown number of shooters were at large at the base in Bathinda city, a defense source told Reuters, declining to be named citing the matter's sensitivity.

An army statement said that four soldiers succumbed to gunshot wounds sustained during the incident, which took place in the early hours of Wednesday morning.

The statement did not mention the circumstances or other details about who was responsible for the incident.

The incident was "not a terror attack," and took place in a canteen, a senior police official in Punjab, S.P.S. Parmar told Reuters.

The base was sealed off and a joint investigation with the local police was on, the army statement said, adding that no other injuries and damage to property were reported.

"All aspects including the possible case of involvement of an (assault) rifle along with 28 rounds reported missing two days back are being ascertained," the army said.

Visuals from Reuters partner ANI showed barricades placed on the road outside the gates of the military station and security personnel deployed outside the boundary wall.

The incident took place at 4:35 a.m. (11.05 p.m. GMT Tuesday), an earlier army statement said.

The military base, about 280 kilometers (175 miles) northwest of New Delhi, houses mostly families of soldiers. The border with Pakistan is about 100 kilometers west of Bathinda.