Five thousand people in northern India have been evacuated as fears grow that a lake in Tibet may overflow and flood the state, officials say.
Residents of nearly 60 villages living along the banks of the Sutlej river in Himachal Pradesh have moved to higher areas, they say.
India says the situation is serious as water is now overflowing from a dam on Tibet's Parechu lake.
Indian satellite images show that the level of the lake in Tibet has risen.
Authorities are keeping a close watch on the level of water in the Sutlej river in Himachal Pradesh for signs of over-flooding from Tibet.
'Taking no chances'
The water level in the Sutlej was "normal" on Friday morning, and it was "slightly muddy in colour," the state's chief secretary Shamsher Singh told BBC News Online
"But we are not taking any chances. We are prepared for the eventuality of over-flooding," he said.
Mr Singh said there was a round-the-clock watch on the water level in the river by authorities and security forces posted on watch towers.
The army is also on standby, and its helicopters have been making aerial surveys.
A wireless network along the banks of Sutlej River in the state had been set up to be used for warning and alerting locals in case the water level rises in the river.
Mr Singh said most of the villagers evacuated from the banks on the river had moved in with their relatives and friends in the upper reaches of their villages.
"A few have moved into government shelters, where we are providing food," he said.
Otherwise, life is said to be normal in the area with public transport and trucks carrying crops to the market plying on the road.
India says that the Chinese authorities had informed that there the water from the lake on Parechu was "overflowing smoothly".
"It is raining intermittently in the area now. If it begins to rain continuously, then the situation will become very dangerous," a spokesperson for the Chinese Embassy in Delhi, Delhi, Yang Shuying, told BBC News Online.
"We are not out of danger yet. There is still a danger of over-flowing."
The Indian states of Himachal Pradesh and Punjab have been on alert since early August, and thousands of people have been evacuated after China warned that water from the melting glacial lake in could spill into northern India.
The lake has been created by a landslide in the Parechu river in Tibet. It is located some 35km from the Indo-China border.
The Parechu, which drains into a tributary of the Sutlej river, has been blocked by a landslide since last July.
The blockage of the river has happened in Tibet's Ali Prefecture "that features high altitude, remoteness, difficult terrain, poor transportation and communication," said Ms Yang.
Floods have hit millions of people in the region
Parts of South Asia have suffered heavy flooding in the past month, leaving hundreds dead.
On Monday, emergency teams rescued 20 workers from a tunnel at Kullu to the north-west of the Sutlej.
The construction workers were trapped after a storm blocked the entrance to the tunnel.