Earlier, the provincial authorities had issued medium-danger avalanche warning in the upper reaches of Kashmir following predictions of inclement weather.
The bodies of the soldiers have been recovered, the official said.
They said intelligence inputs suggest that there are large number of militants waiting in launch pads near the LoC in north Kashmir to sneak into this side even during winter months. The SASE has advised people in these regions to avoid venturing into avalanche prone slopes during the warning period.
The avalanche hit an army post near the Line of Control around 11:20 am, defence ministry sources told news agency IANS.
Soon after the incident, search operation was started and all the three soldiers trapped under snow were evacuated.
The condition of the injured soldier Sepoy Bipin is stated to be stable.
While two soldiers had slipped down a mountain slope in Nawgam sector of Kupwara district, three others went missing from a forward post in Kanzalwan sub-sector of Gurez in Bandipora district during heavy snowfall on Tuesday.
The three deceased soldiers have been identified as Havaldar Kamlesh Singh (39), Naik Balveer (33) and Sepoy Rajinder (25).
Last January in a series of four avalanches 24 people, including 20 soldiers and four civilians had died.
In December past year, two soldiers were killed in avalanche.