Kathmandu, Nepal: Thousands of panic-stricken villagers fled their homes fearing flash floods after an overnight landslide blocked a river in quake-hit Nepal's mountainous north-west, officials said Sunday.

The landslide, which occurred at around midnight, sent mud and rocks surging into the Kali Gandaki river in Myagdi district, causing water levels to rise by 150 metres (490 feet), local official Yam Bahadur Chokhal said.

‘We have evacuated about 100 people from the affected area, people in other villages don't need immediate rescue but thousands have left on their own,’ Chokhal told AFP.

The region has witnessed several small landslides in recent days, according to local official Trivikram Sharma, based in the district headquarters of Beni, 185 kilometres (115 miles) west of Kathmandu.

‘After the two quakes, villagers have reported several minor landslides and late last night, they said the hill just came down,’ Sharma told AFP.

‘We cannot immediately assess the risk of flash floods but people are obviously scared that the artificial dam will burst suddenly and submerge their homes,’ Sharma said.

No one was hurt or killed in the landslide, according to officials.

An army helicopter carrying soldiers and experts was on its way to help open the blockage and drain the artificial lake created by the landslide.

Police have issued an alert for villagers living along the river, which begins near the Nepal-China border and flows into northern India, eventually joining the Ganges.

The snow-fed waters are also the site of Nepal's largest hydroelectric project that generates 144 megawatts of power, located south of the landslide-blocked area.

Twin quakes have devastated Nepal in recent weeks, killing more than 8,600 people, while leaving thousands in desperate need of food, clean water and shelter.