The landslide blocked a mountain river in Nepal, causing it to back up and form a massive lake that is threatening to overflow and flood the Indian villages.
"We are keeping our fingers crossed right now," said Aniruddh Kumar, a senior disaster management official in India's Bihar state. He said it is still not clear how much water might come down from the lake.
Nepal's army triggered three controlled explosions Saturday to allow some water to flow out of the lake, but much of it remains trapped.
Kumar said Bihar state has asked all government doctors and civil officials in threatened areas to cancel vacation plans. Indian soldiers, as well as air force helicopters and jets, were on standby for relief and rescue operations.
The local government also invoked a law allowing authorities to forcibly evacuate villagers who refuse to leave their homes and property and move to higher ground or government-run relief camps. The government has so far evacuated 60,000 people and set up 120 such camps.
Kumar said all public schools in the area have been closed to provide space to house the large number of people being evacuated.
The annual monsoon season, which runs from June through September, is vital for the largely agrarian economies of South Asia but every year also brings floods and landslides that kill thousands and submerge hundreds of villages.
Another landslide hit in a village in eastern Nepal on Monday, killing four people and leaving six others missing. And the death toll from a massive landslide in western India last week rose to 108, according to rescue official Sandeep Rai Rathore.
Associated Press writers Binaj Gurubacharya in Katmandu, Nepal, and Niranjan Shreshtha in Mankha, Nepal, contributed to this report.