Chandigarh, April 29 -- A pro-Khalistan terror module carried out a late-night blast at a freight corridor railway track near the Shambhu area in Patiala, in which one of its members was killed while attempting to detonate the explosives, police said on Tuesday, adding that four members of the module have been arrested. The explosion, which occurred on Monday night on the Shambhu-Ambala rail track, was initially described as a low-intensity blast. However, an investigation later determined it was an attempt to blow up the track, police stated. The explosion occurred near Bothonia village on the rail track dedicated to freight trains, causing damage and leaving a small crater beneath the railway line, police said. Noting that the incident marks the second blast at a freight corridor in the past three months, a senior police officer indicated that a NIA probe into the matter is likely. The person who was trying to carry out the detonation died in the attempt, Patiala SSP Varun Sharma said. Police identified the deceased suspect as Jagrup Singh, a resident of Panjwar village in Tarn Taran district. Deputy Inspector General of Police Kuldeep Chahal stated that the four arrested individuals are Pardeep Singh Khalsa, a resident of Mansa; Kulwinder Singh, also from Mansa; and Satnam Singh and Gurpreet Singh, both residents of Tarn Taran....