Srinagar, India (CNN) -- An Indian army trooper gunned down two of his colleagues with his service rifle in the frontier Poonch district of Indian-administered Kashmir on Sunday before turning the gun on himself.
"Senior army officers have rushed to the spot to investigate," an Indian defense spokesman said.
"The army has also ordered a court of inquiry to ascertain the facts," defense spokesman Col. Manish Mehta told CNN.
This is the second fratricidal incident in Indian-administered Kashmir this year. In February, five troopers were shot dead by a colleague before he killed himself.
Senior security force officers attribute the problem to stress because of long duty hours.
Several remedial measures -- including granting periodic leaves, bringing in counselors and providing recreational facilities -- have been put in place.
Kashmir is a mountainous region that has long been the subject of dispute between India and Pakistan. Both sides keep large numbers of troops in the region.
Since 1989, India has also been fighting against a violent separatist movement in the mainly Muslim area it controls, a conflict that has killed tens of thousands of people.