We can not lower the guard because of avalanche warning as the threat of infiltration from across the LoC remains there even during winter, they added.
The bodies of the soldiers have been recovered, the official said.
Avalanches and landslides are common in Himalayan Kashmir. The SASE has advised people in these regions to avoid venturing into avalanche prone slopes during the warning period.
The police and Army sources said a forward post of the Army's 21 Rajput at Sona Pindi Gali was hit by an avalanche at around 4:30 pm. One soldier reportedly died on the spot, and two others succumbed to their injuries while being transported to the base hospital at Badami Bagh cantonment near Srinagar.
In a tweet the Northern Command said " ArmycdrNC and all ranks salute the supreme #sacrifice of three #soldiers who got swept away in an #avalanche in #Machil sector on 02 Feb 2018 and offer condolences to their families".
Defense spokesman Rajesh Kalia told The Indian Express that three soldiers were killed when the Army post was hit by an avalanche in Machil sector. They were there defending the country. Earlier in the first week of January, eleven people, including a Border Roads Organisation officer and a year-old baby girl died when snow avalanches hit at two places in Tangdhar area of Kupwara. In the past, many soldiers have become victims of avalanches.