Patiala, April 30 -- A suspected railway track bomber was in contact with a Malaysia-based handler, identified as Jujhar Singh, through the encrypted messaging app 'Threema', according to officials investigating the case. Punjab Police officials said 'Threema' is a paid, cross-platform encrypted instant messaging app that offers end-to-end encryption. Additionally, it does not require a phone number or email address for registration. The accused, Jagroop Singh from Panjwar Khurd village Tarn Taran, was killed when an improvised explosive device detonated prematurely during an attempt to target a freight railway track at Bathonia near Shambhu in Patiala on Monday night. Following the incident, Punjab Police uncovered a Pakistan-linked terror module and arrested four individuals in connection with the failed sabotage attempt on the Rajpura-Shambhu railway line. Investigators identified Pradeep Singh Khalsa as the alleged kingpin of the module. He is suspected to have maintained links with handlers in Malaysia and Pakistan to coordinate attacks on public infrastructure. The probe has revealed that Jagroop travelled to Malaysia multiple times between 2014 and 2022, where he is believed to have established contact with operatives and other members of the network. Punjab director general of police (DGP) Gaurav Yadav said that Jujhar, who was controlling the operatives of this module, was further in touch with USA-based Surinder Singh Thikriwal, who has been involved in several previous terror modules, while Pakistan-based Ranjeet Singh alias Neeta - a designated terrorist - was also in touch with this module through a well-layered network. Police officials are also examining his possible involvement in earlier incidents, including a blast in Sirhind earlier this year and another explosion outside the CIA premises in Moga. Authorities noted that Jagroop had previously been questioned in a graffiti case in Barnala last year but was not detained. A local court granted seven-day police remand of the four arrested accused - Pradeep Singh Khalsa, Kulwinder Singh Bagga, Satnam Singh Satta and Gurpreet Singh alias Gopi - to facilitate further interrogation and to uncover the wider conspiracy. The banned outfit Khalistan Zindabad Force has claimed responsibility for the blast, issuing a threat of further attacks in an audio clip attributed to its operative. Two days after an IED blast on the Rajpura-Shambhu railway line, Patiala Police, in a joint operation with the State Special Operations Cell (SSOC) Amritsar, has averted major terror plots with the recovery of a cache of militant hardware, including a rocket propelled grenade (RPG), hand grenade, explosives and high-end pistols from Panjwar Khurd village in Tarn Taran. The recovered military hardware includes one RPG, one metallic IED (sticky bomb) weighing 2.296 kg along with three detonators with electric wire and one battery, two packs of RDX weighing 1.456 kg, one P-86 hand grenade, three pistols - 9MM Glock-18 CX 'Austria', .30 bore PX5 Storm and .30 bore Star Mark - along with five magazines and 84 live cartridges, two wireless sets Baofeng, one headphone and two timer switches, police said. The development came in continuation of the probe into an explosion at a railway track near Shambhu in Patiala district on Monday night, which resulted in the death of Jagroop, who was attempting to plant an IED. The DGP said this recovery was based on the disclosures by the arrested accused Satnam alias Satta - brother of prime accused Jagroop....