" Aaj Patna Junction ko uda denge. Rok sako to rok lo (I will blow up Patna Junction. Prevent it, if you can) - the message sent in chaste Hindi to the superintendent of police (security) sent top government railway police (GRP) officers into a tizzy on Wednesday morning.

Within no time, cops deployed at Patna Junction were put on a high alert and asked to carry out checks in all important trains crossing the station. Sniffer dogs and bomb disposal squad personnel were also pressed into service to assist the search teams. The passengers were asked to vacate railway platforms temporarily as a precautionary measure.

Sources said SP (security) Deepak Burnawal received the message from cellphone number 91556 30911 at 6.36 am. Burnawal immediately contacted inspector-general (railways) Amit Kumar, who warned the GRP officers. Patna SP (rail) P.N. Mishra and other senior officers were asked to rush to Patna Junction and carry out checks.

Amit later told The Telegraph that the mobile SIM, which was used for sending the threat message twice, has been traced and efforts were on to arrest its owner. "We have taken all precautionary measures keeping in mind the forthcoming Assembly polls. Police are carrying out elaborate checks," he added.

The sources said the identity of the message's sender has been ascertained. He is stated to be a resident of the Sikarpur police station area in West Champaran district. "He is working as an agent for a bank at Narkatiaganj. Some local residents identified him with the photograph sent to the local police on WhatsApp," an investigating officer said.

The photograph of the message sender was obtained from the cellphone company, which had issued the SIM to the man. "It would not be justified to disclose the name of the sender as it would hamper investigation," the police officer on condition of anonymity said.

Over a dozen trains, including Bandra-Patna Express, Akal Takht Express, Shramjivi Express, Howrah-Delhi Express among others stationed at Patna Junction were searched by separate police teams. In the process, some trains got delayed by a few minutes. The railway protection force (RPF) officers were also seen carrying out searches at the platforms.

Frisking of passengers and checking of vehicles parked on the station premises that started at 7am was continuing till late in the evening. Though a few passengers opposed police action, security men were in no mood to let off. "We don't want to take any chance," a member of the search team told an elderly couple proceeding towards the station.