A temporary crossing over the flash flood area was built by the army.
The Army rescued around 3,500 tourists who were stranded in North Sikkim due to landslides and roadblocks, said officials.
Troops of Trishakti Corps, the Army and personnel of Border Roads Organisation worked collectively.
Sikkim's Lachen, Lachung and Chungthang valleys on Friday were hit by heavy torrential rain. As a result, the road from the North Sikkim district headquarters Mangan to Chungthang was blocked at Pegong Supply Khola and vehicular traffic was disrupted, officials added.
Troops of Trishakti Corps, the Army and personnel of Border Roads Organisation worked collectively during heavy rain and inclement weather to rescue the tourists.
A temporary crossing over the flash flood area was built and the tourists were assisted in crossing the river. They were provided hot meals, lodging and medical support.
Over 2,000 tourists were rescued till 3 pm today. 36 foreign tourists were also stranded at hotels in Lachen and Lachung areas - considered gateways to various places with scenic beauty.
The Indian Meteorological Department (IMD) has also predicted heavy to very heavy rainfall over Northeast India and Sub-Himalayan West Bengal and Sikkim during the next 5 days.
Efforts are on to restore road connectivity, while the evacuation of tourists is in full swing.