Thousands of people fled villages and towns along a mountain river in in northwest Nepal on Sunday after it was blocked by a landslide that could burst and cause flash floods, officials said.

The landslide created a dam and a lake 2 kilometers (1.2 miles) long on the Kaligandaki River, said government administrator Yam Bahadur Chokhal.

Residents living on the banks of the river were moved to higher grounds for fear the river could burst and send flash floods through the area north of Beni Bazaar, about 200 kilometers (125 miles) northwest of the capital, Kathmandu.

Soldiers and police officers were sent to monitor the river and help and warn the villagers.

Two powerful earthquakes devastated Nepal on April 25 and May 12, killing nearly 8,700 people and injuring 16,800 others. The quakes and aftershocks also triggered many landslides in the Himalayan nation.

In 2002, dozens of people were killed when an avalanche held back the nearby Seti River, which then burst through the snow blockage and sent water gushing through villages along its banks.