The teenager, identified as Sanjib Das, found the detonator attached to a wire at a stone quarry on the Assam-Meghalaya border and was carrying it home at Uday Nagar here when it exploded in the high security area, IGP (Central Western Range) L R Bishnoi told PTI.
The IGP said the teenager suffered minor injuries in the explosion which was a small one and caused no damage.
He said that Das was administered first aid at a hospital and released.
The area around the chief minister's official residence was cordoned off and security measures tightened.
Das is a school student of class nine, official sources said. Such detonators for use in blasting stones, sources said.