CRPF Constable Ajit Singh fired shot dead the three colleagues inside a camp in Battal Ballian area on Wednesday night after a heated exchange of words, a police officer said.
The incident occurred around 10.40 p.m.
Ajit Singh belongs to Kanpur in Uttar Pradesh. The deceased were identified as Head Constables Umeed Singh of Rewari (Haryana), Yogendra Sharma (Delhi) and Pokarmal of Jhunjhunu (Rajasthan).
This is the first fratricidal incident of this year in Jammu and Kashmir.
Security forces have in the past engaged counsellors to address the problem which have been attributed to long duty hours in hostile environment, separation from families, lack of recreational activities and a weak command and control structure.
Better command and control, frequent leave facilities to join families and adequate recreational facilities are some of the remedial measures suggested by counsellors to address the problem.