The fatal incident happened late Saturday evening inside the Central Reserve Police Force (CRPF) camp in the Himalayan town of Kulgam, about 90-minutes drive from Srinagar, the capital of Indian-controlled Kashmir.[break]
"We have three CRPF personnel dead and one injured," a police officer told AFP, speaking on condition of anonymity because he was not authorised to speak with the media.
Other personnel inside the barracks at the time of the shooting were detained for questioning, he added.
It was not immediately clear if there was one or more shooters responsible for the deaths.
Around 100 Indian security force personnel commit suicide every year in Kashmir and the insurgency-racked northeastern states, according to official figures.
There have also been a raft of incidents involving soldiers shooting their comrades and officers, known as fragging, which have been blamed on stress.
Indian soldiers battling a 20-year-old insurgency in Kashmir are now being provided a 24-hour helpline and meditation classes to overcome stress, although fragging incidents in the region have dropped as the insurgency slowed.
More than two decades of violence in Kashmir has left more than 47,000 people dead by official count.
India and Pakistan, which each hold the region in part but claim it in full, started a peace process in 2004.
Indian police say gun battle has ended at Kashmir army camp