Investigators outside the PMO after the firing. (PTI)

New Delhi, March 28: Two police guards fooled around with a gun in the parking lot of the Prime Minister’s Office today, with one of them “accidentally” shooting the other in the thigh.

Red-faced police sources blamed the two men’s “irresponsibility” for the fourth serious breach of Manmohan Singh’s security in the past 20 months.

Head constable Suraj Pal, stationed outside the PMO for years, shot and injured younger colleague Sanjay Kumar with his service revolver while teaching him how to use the gun.

“They were learning how to handle the gun,” an officer said. “It was not the place for them to train each other. This is a high-security zone with Rashtrapati Bhavan next door and all the important ministries around.”

Kumar is at Ram Manohar Lohia Hospital where surgeons have removed the bullet from his thigh, while Pal is being questioned in custody. Both have been charged with negligence in using a firearm.

The early afternoon shooting in the duty-change cabin had the police brass running to the spot as rumours about a “fight” between two guards swirled.

The police later denied this. “The service revolver was mishandled. There is no suggestion of this being the result of a fight,” the police spokesperson said.

In July 2006, a group of high-spirited young men and women had driven past security and entered the Prime Minister’s residence. Months later, Singh’s motorcade had veered off the scheduled route on a Kerala trip.

Last year, Congress leader R.K. Dhawan’s helicopter had intruded into the restricted airspace around Singh’s convoy.