In a breakthrough in the investigation into the July 8 grenade attack on Sadar Police Station, Moga, the police have arrested another key suspect, taking the total number of arrests in the case to 18.The terror module, allegedly operated by foreign-based handlers, was reportedly plotting to plant an improvised explosive device (IED) on a running train on the Ferozepur-Jammu route.According to police sources, the low-intensity grenade attack had occurred around 3.15 am on July 8 at the Sadar Moga police station premises. Subsequent raids led to the arrest of three main executors who carried out the attack on a motorcycle — Gagan alias Kali, a resident of Dheru in Ferozepur; Rajesh alias Khanna, a resident of Lal Kurti Cantt, Ferozepur; and Shubham alias Bhinder, a resident of Kotwal, Ferozepur.The police said the conspiracy was masterminded remotely from abroad by Iqbal Singh alias Ravi Dhaliwal, currently based in the United Kingdom, who was directing operations and local recruitment. Kuljeet Kaur, a native of Ferozepur residing abroad, along with Lajjar alias Aman and his wife Parveen Kaur, residents of Sia Paadi in Ferozepur, served as key links providing logistical support, funds and safe houses to the module. The police said Swaran, Gobind, Sagar and John, all residents of Ferozepur, were also arrested for harbouring module members and assisting with the operation.Following the interrogation of Lajjar alias Aman, police recovered a live IED fitted with an electronic detonator that was intended for the train attack, a 9 mm Glock pistol with a magazine, and the Hero Splendor motorcycle used in the police station strike. Cases have been registered under the Unlawful Activities (Prevention) Act, the Explosive Substances Act and the Bharatiya Nyaya Sanhita. The police said further investigation was under way to dismantle the remaining linkages of the overseas network.