A 56-year-old security guard deployed at Naval Armament Depot (NAD) in Trombay allegedly shot himself with a rifle. The police are working out why Kesar Singh took the step on Thursday morning.

According to the Trombay police, Singh was working as a guard with Defence Security Corps (DSC) and had been deployed at NAD for the past few years. The other on-duty navy personnel told the cops that Singh was stationed for sentry duty on the watchtower at NAD premises.

"Between 11-11.30 am, officers heard the sound of a rifle going off, after which Singh was found dead inside the watchtower. Preliminary investigations reveal that Singh shot himself in the head with a 7.62 mm self-loading rifle. He was rushed to a nearby hospital where he was declared dead before arrival," said the investigating officer.

"We haven't recovered any note from the spot or from the quarters where Singh stayed with 29 other officials," said the officer. Singh was supposed to go on a leave to meet his family in Punjab. He was on good terms with all the officers, and his colleagues said he seemed healthy and sound, the officer said, adding that the motive behind the act is being investigated. The body will be handed to Singh's family after the postmortem at JJ Hospital. The police have registered an accidental death report.