The Pakistani intruders were shot dead at Mullapur village during the cross firing with night patrolling party of BSF.
The three intruders opened fire when they were challenged by the BSF night patrolling party who then responded killing the trio, BSF officials said.
A search operation was launched this morning during which bodies of the slain intruders were found, besides, 24 kg heroin worth Rs 120 crore in the international market.
A senior official said that the search operation was still in progress. More recovery of drugs and arms is expected after completion of search operation.
