A car alarm activated mistakenly cut short a burglary in a house in Salt Lake’s AB block on Thursday night. Rekha Haldar, who worked as a help in the house, has been detained.

A gang broke into the first-floor apartment of 80-year-old Nripendranath Sanyal, a former bank official, but while cleaning out an almirah, one of the criminals mistakenly pressed the remote control of the locking system of the family car.

Sanyal said that as the alarm went off, Rekha alerted the family members, prompting the burglars to flee.

He recalled seeing “a few men” hurriedly climb off the balcony. Debabrata Das, the additional superintendent of police, Bidhannagar, said: “The gang fled with Rs 10,000. The flat owner has also complained that a sweater was missing.”

Sanyal said he had not locked the balcony door on Wednesday night.