Four Army jawans were killed in firing inside a military station in Bathinda in Punjab early Wednesday, with the state police registering a case against two unidentified persons.

The four personnel, in their mid 20s, were sleeping when the firing took place around 4:30 am in a barracks near the officers' mess in the artillery unit.

A jawan saw two unidentified men in white kurta-pyjama, their faces and heads covered, coming out of the barracks after the firing. One of them was carrying an INSAS rifle and the other an axe, the jawan said, according to the police FIR.

According to "the information we have gathered so far, it is clear that it is not a terrorist act," a senior police officer said.

Initially, the police suggested that it was an incident of "fratricide". However, officials later said there was no clarity on the incident yet.

It is learnt that Army Chief Gen Manoj Pande briefed Defence Minister Rajnath Singh on the matter.

Army sources said a court of inquiry (CoI) will investigate the entire incident in addition to the ongoing probe by the state police with support from the force.

It is suspected that an INSAS rifle, which was reported missing along with 28 rounds two days ago, was used in the firing incident. The Army said on Wednesday the INSAS rifle has been found.

The two suspected attackers, who were of medium height, went towards a forested area near the barracks on seeing the jawan, who later reported the matter to the police.

Subsequently, two Army officers went inside the barracks and found Sagar Banne (25) and Yogesh Kumar J (24) in a pool of blood. In another room, the bodies of Santosh M Nagaral (25) and Kamalesh R (24), were found. The bodies bore bullet marks, according to the FIR.

Two of the slain jawans hailed from Karnataka and the other two from Tamil Nadu.

The Bathinda military station is one of the largest Army bases in the country and it comprises a significant number of operational units of the force.

"It has been ascertained that in the unfortunate incident, four army jawans of an artillery unit succumbed to gunshot injuries sustained during the incident. No other injuries to personnel or loss/damage to property have been reported," the Army's South Western command said in a statement.

After the firing incident, the Army deployed quick reaction teams and cordoned off the area.

It said the area remained sealed off and joint investigations with the Punjab Police are being coordinated to establish the facts of the case.

All aspects, including the possible case of involvement of the missing INSAS rifle, are being ascertained, it said.

The Army said no individual has yet been detained or apprehended for the killing.

Bathinda Superintendent of Police (Detective) Ajay Gandhi, who headed the police investigation, told reporters that 19 empty shells of an INSAS rifle were found from the spot.

According to the Army statement, "Army and Police Joint teams will now be undertaking forensic analysis of the weapon for ascertaining further details. The balance number of rounds in the weapon will only be available after forensic analysis." "The joint investigation with Punjab Police is in progress. All possible assistance is being provided," it added.

Gandhi said CCTV footage is being scanned and the Army is conducting a cordon-and-search operation and the entire area has been sanitized.

Asked if it could be a fratricidal incident, Gandhi said, "Investigations are on." Bathinda Senior Superintendent of Police Gulneet Singh Khurana said in the evening, "As per the information we have gathered so far, it is clear that it is not a terrorist act." Earlier in the day, Khurana, while referring to the incident, said, "It is an internal issue, it appears to be fratricidal issue." Punjab's Additional Director General of Police SPS Parmar earlier in the morning made a similar observation, saying "It is not a terrorist attack, it is not an attack from outside. It is a fratricidal incident." Based on a complaint filed by Army Major Ashutosh Shukla, an FIR was lodged at Bathinda Cantt police station under IPC Section 302 (murder) and relevant sections of the Arms Act against two unidentified persons, the police said.

Bathinda Cantt Police Station SHO Gurdeep Singh, when asked if the police received any complaint about the missing INSAS rifle, he said they got the information on Tuesday evening.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.