Up to 33 soldiers may have died after falling into a river in the north Indian state of Himachal Pradesh.
The soldiers fell into the icy river when a bridge they were working on collapsed, officials say.
The incident took place at Kharo in Kinnaur district which has recently experienced severe flooding after a lake burst its banks in nearby Tibet.
The deaths are not yet confirmed. A rescue attempt is being hampered by the poor weather, according to an official.
Colonel Anurag Bhasin told the BBC: "Although we do not have any confirmation of any death so far, we fear many may have been killed as the icy river current is very swift and the waters deep."
Much of Kinnaur district remains cut off from the rest of the country following flash floods in June which washed away roads and bridges.
"We're trying to fly rescue teams from Chandigarh to Kinnaur but the weather is not conducive," Colonel Bhasin said.