Five people have been arrested and arms have been seized, police sources told IANS.
The development came following an attack in Doda district last week, during which two special police officers (SPOs) were injured with one subsequently succumbing to his injuries, a source said.
A special investigation team (SIT), headed by Doda police chief Muhammad Shabir, was set up to investigate the firing incident at Tanta police post in Doda district on May 7 and after visiting the spot, conducted preliminary investigation along with a team of forensic experts.
"From intelligence generated through local sources, the SIT picked up some suspects and based on their disclosure, apprehended Abdul Rashid Harga alias Abdullah, a resident of Tanta village who had remained an active militant of LeT from 2001 to 2008 but had later surrendered," the source said.
On sustained interrogation, Mr Harga, who had again been arrested in 2013 but bailed out in 2016, confessed his involvement in the firing incident and disclosed name of his two associates, namely his younger brother Shoket Ali and Akthar Magary, both residents of Tanta, the source said.
Interrogation of all three led to the entire chain of events leading to the attack becoming known, the source added.
According to the source, Mr Harga was in contact with Bashir Ahmed, who was earlier working in the Territorial Army and whose nephew Altaf Ahmed was a SPO in Doda, and asked him to arrange a weapon for him.
Altaf Ahmed managed to steal an AK-47 rifle along with ammunition from district Police Line in Doda in January 2017 and handed it over to his uncle.
Meanwhile, Mr Harga was in direct communication with his Pakistani handler, Mohammad Amin alias Haroon of LeT.
"On the direction of Haroon and commanders of Valley-based militant organisations, who were asking him to activate militancy in Doda, Harga activated his newly-recruited grid to keep vigil on the movement of security forces/police pickets in remote hilly areas of Gandoh belt and planned to attack the security forces.
"On May 7, Harga had a recce of the police picket at Tanta, got information that only two to three men were there and attacked the post, injuring the SPOs," the source said.