A day after a Central Industrial Security Force constable shot himself dead in Delhi, a 40-year-old member of the force posted at the airport in Varanasi on Thursday committed suicide while on duty apparently due to some family problem.

Constable Bal Krishna Sharma, posted near the runway of Badatpur Airport, turned his service gun on himself at around 1900 hours, police sources said.

Sharma, a resident of Mathura, had returned from a short-duration leave about 15 days back and had looked tense since then, they said.

The airport was sealed soon after the incident.