New Delhi, May 22 -- The National Investigation Agency (NIA) has arrested a key associate of two Khalistan Liberation Force (KLF) linked terror operatives who had carried out a grenade attack on a temple in Punjab's Amritsar in March this year, the agency said on Thursday.

Absconder Bhagwant Singh alias Manna Bhatti was nabbed on Wednesday from Akalgarh village in Amritsar, taking the total arrests in the case to four.

The attack was carried out by Gursidak Singh and Vishal alias Chuchi, who had hurled a hand grenade at Thakur Dwara Sanatan Mandir in Amritsar, the NIA investigation reveals. The proscribed terror organisation KLF has claimed responsibility for the attack.

While Gursidak Singh was killed in a shootout with police followi...