A tourist slipped into a river in North Sikkim district while clicking selfies, police said on Tuesday.
Abhishek Kumar (21), a resident from Bihar, was in Lachung town on Monday, they said.
While clicking selfies, he slipped and fell into the Lachung river around 7.30 am, they added.
An operation was underway for more than 24 hours to rescue Kumar, officials said.
Personnel of the Indo-Tibetan Border Police (ITBP) and Sikkim Police were engaged in the search operation, they said.
Officials of the Travel Agents Association of Sikkim, and locals were assisting the forces in the search for Kumar, they added.
Lakhs of tourists visit the remote Lachung and Yumthang valley, near the India-China border, every year to enjoy its picturesque landscape and apple orchards.