Enquiries made by Newsline revealed that an ASI of the General Railway Police (GRP), Ravinder Mohan, who had gone from Rajpura to Shambhu to conduct a check on a police picket, spotted a "suspicious-looking bag" on the Ghaggar Bridge, two to three feet away from the railway track.

The police officer also found some wires sticking out of the bag and reportedly pulled them out to render the device ineffective. Senior officers of the district, including Deputy Commissioner Jasbir Singh Bir and Senior Superintendent of Police Parampal Singh Sidhu were among those who visited the site at around 4 a.m.

The traffic on the rail line was stopped immediately and several Up and Down trains were held up for over two hours. Rail traffic was resumed at around 5 a.m. this morning. The trains hit by the delay included the Flying Mail and the Delhi-Amritsar Super Express.

The explosive device was fitted with an HMT watch and was set at 2 a.m. If the the device had not been detected and defused, it would have caused a major blast, the railway authorities said.

Experts of the Forensic Science Laboratory confirmed that the explosive material packed in cardboard boxes and kept inside the bag was indeed RDX.

Patiala DC Jasbir Singh Bir confirmed that a bag containing explosives was found.