NIA searched 10 locations in three Punjab border districts, seizing digital devices and documents.
Probe links the Amritsar temple grenade attack to foreign-based handlers funding and directing operatives.
One accused has been arrested, another is dead; explosives supplier was earlier arrested in Jharkhand-Bihar.
In relation to the 2025 Amritsar temple grenade terror attack investigation, the NIA searched several locations in three border areas of Punjab on Thursday.
According to a statement from the National Investigation Agency, incriminating items were found during the searches, which were conducted at ten locations in the districts of Amritsar, Tarn Taran, and Gurdaspur.
"A host of incriminating materials, including mobiles/digital devices and documents, were seized during the searches," it said.
The case pertains to an explosion outside the Thakur Dwara Sanatan Temple at Khandwala on Sher Shah Road in Amritsar on the night of March 14 last year.
"The attack was carried out on the directions of several foreign-based handlers, who had arranged for explosives and weapons to spread terror in the region," the statement said.
It added that the temple attack was "among many such grenade attacks carried out by operatives of different terror groups in the state of Punjab as part of the terror conspiracy".
According to the NIA, the inquiry also showed that the "foreign-based handlers" had been financing and recruiting numerous people in India to carry out these grenade assaults.
The NIA discovered that suspects Vishal and Gursidak had thrown the grenade into the Amritsar shrine after taking over the investigation from the state police.
Gursidak has already passed away, but Vishal has been taken into custody.
The federal agency claims that Sharanjeet Kumar of Qadian in Batala, who escaped to Jharkhand and Bihar before being apprehended in September, gave the two the bomb.
"Sharanjeet, who had received consignments of explosives and grenades from foreign-based handlers, had also concealed three hand grenades and one pistol," the statement said, adding that these were later recovered from a location in Gurdaspur district.
