Police sources said, the firing took place around 5 A.M. when a Police team stopped a Srinagar-bound truck for checking near the busy toll plaza in Ban area of Nagrota.
On being stopped the terrorists travelling in the truck fired indiscriminately at the security forces and tried to flee from the spot. The fleeing terrorists were intercepted soon after the attack resulting in a gunfight.
In the ensuing gunfight, three terrorists were killed while search operation is on to track one more suspected terrorist.
Police sources further said that the terrorists were part of a freshly infiltrated group, who have entered this side from the International Border in Hiranagar in Kathua district and were on their way to Kashmir Valley.
Four weapons and some ammunition and explosives have been recovered from the spot.
Traffic has been suspended on the busy highway after the attack and authorities have ordered closure of schools in Nagrota as a precautionary measure.