The incident happened in the early hours yesterday when the suspect, who tried to break open the ATM, left the place after failing in his attempt and pulled down the shutter of the kiosk, police said.
The victim, who hails from Assam, bled to death due to head injury and his body was found with hands and legs tied up and his mouth plastered, they said.
The incident came in the light when some customers visited the ATM on the first floor of the building and found the guard's body in the enclosed space, police said.