Security forces launched a cordon and search operation at Hanjin village in Rajpora area of the district, following information about presence of militants there, a police official said.
He said the search operation turned into an encounter after militants opened fire on the security forces, who retaliated.
One soldier was injured in the initial exchange of firing with militants, the official said, adding that the jawan succumbed to injuries at a hospital here.
The official said reinforcements were rushed to the area and in the exchange of firing, three militants were killed.
The identities of the slain ultras were being ascertained, he said, adding that they belonged to LeT group.
The operation is going on and further details were awaited, he added.