“An improvised explosive device was found inside a black and red colour school bag from bogie number five,” the clearance certificate from the BDU said.

The bag contained a time bomb attached with a battery. The explosive material weighed around two and a half kilogramme and an electric detonator with a mortar container was attached to it.

A heavy contingent of law enforcement agencies and Rangers cordoned off the area after the bomb was found.

All the material was handed over to police, said the certificate.