MUMBAI: A pendant with a QR code helped police reunite a mentally unwell 12-year-old boy with his parents, a Mumbai police official said on Friday.

The child was spotted wandering in Colaba in the southern part of the city on Thursday afternoon, he said.

"The child was not able to tell anything cohesively to people who approached him after realising he may be lost and in distress. One of them brought him to a policeman. An alert about a missing person was sent to all police stations but in vain," the official said.

"One of the police personnel found a pendant around the child's neck. He found a QR (quick response) code inside, which when scanned revealed a phone number. It belonged to an NGO that works for mentally unwell children," he said.

A functionary of the NGO told police the child was a resident of Worli and his parents were looking for him since morning, the official added.

"The child was reunited with his father at the police station some time later. It was great relief to us that we could get the child safely back with his parents," the official said.