NEW DELHI - India has begun work to designate as dead at least 79 people who went missing in floods unleashed by a Himalayan glacial lake outburst two weeks ago, a senior official said on Friday, taking the death toll in the disaster to 179.

The floods triggered by torrential rain and overflow from the Lhonak Lake were among the region's worst in more than 50 years, washing away homes and bridges in the northeastern state of Sikkim, wedged between Bhutan, China and Nepal.

The state government has begun the process for such a designation of those still missing, by seeking the federal government's permission, since the law specifies an interval of seven years before a missing person can be declared dead.

"We have not called off the rescue efforts, but after two weeks it will be a miracle (to find them)," said state official Anil Rai.

Sikkim retrieved at least 40 bodies in the flood aftermath and the neighbouring state of West Bengal 60, said officials from the two states who are working to reconcile the official toll and eliminate double counting.

As climate change warms high mountain regions, many communities face the risk of dangerous glacial lake outburst floods (GLOFs).

Lakes holding water from melted glaciers can brim over and burst, sending torrents rushing down mountain valleys.

More than 200 such lakes now pose a high hazard to Himalayan communities in Bhutan, China, India, Nepal and Pakistan, research in 2022 showed.

(Reporting by Krishn Kaushik; Writing by Shivam Patel; Editing by YP Rajesh and Clarence Fernandez)