Information was received about a part of a glacier collapsing beyond Sumna Chawki near Malari in the Niti valley, Border Roads Organisation (BRO) officials, who were on their way to the spot, said.
No contact has so far been established with the area due to heavy snowfall, they added.
A BRO official confirmed the sliding down of a glacier in the area, where labourers are engaged in road construction work.
A BRO team was rushed to the spot but there is no clue yet on the damage caused, he said.
Chief Minister Tirath Singh Rawat tweeted about the incident, saying an alert has been issued and he is in constant touch with the BRO and the district administration for updates.
In another tweet, Rawat said Union Home Minister Amit Shah has taken immediate cognizance of the incident and assured the state of all help.
Jal Shakti Minister Gajendra Singh Shekhawat said he is monitoring the situation closely.
“Unfortunate that a disaster has struck Reni Village of Uttarakhand owing to a glacier burst on Dhauliganga river.
“I am monitoring the situation closely. CWC is on alert and a team led by a secretary level officer has taken charge of the situation,” he wrote on Twitter.
In February, a glacier burst killed nearly 80 people in Chamoli while many went missing.