The police had received information that the boy was in contact with and was providing information concerning the country's security to Pakistan military officers, ISI and frontal organisations running terror modules in that country, Pathankot Senior Superintendent of Police (SSP) Daljinder Singh Dhillon said.
While Raina's uncle Ashok Kumar, 58, died on the spot, his 32-year-old cousin Kaushal succumbed to injuries on August 31 at a private hospital in Pathankot.
However, no casualty was reported in the blast that took place late on Sunday night in front of Triveni gate of the cantonment.
The ISYF is supported by Pakistan's intelligence agency ISI.
The joint operation of Punjab Police, the Army, the Air Force and the Himachal Pradesh Police was launched following the intelligence input.
Punjab Police conducted search operation jointly with Himachal Pradesh Police in the hilly areas located in Bhadroya which is in Himachal Pradesh and covered almost 5-6 km of forest area in search operation.
Pathankot Senior Superintendent of Police R K Bakshi said that sleuths found that the bag contained uniform, shoes and other articles of an Army jawan who had left it behind.
The search operation was carried out on Friday evening after a farmer claimed to have seen six suspicious persons who were carrying backpacks