Kathmandu: At least two workers building a tunnel at a hydropower project in Nepal were killed and ten injured when heavy rains lashed Kathmandu and other parts of the country on Friday and Saturday, officials said.

Two workers died on Friday after being buried in the tunnel of the Bhotekoshi hydropower project under construction in Sindhupalchowk district, 125 km east of Kathmandu.

Their bodies have been recovered.

As many as 12 workers were buried when the side tunnel of the Jhirpu Electro Power Company Limited dam, which is under construction in Bhotekoshi Rural Municipality, collapsed following heavy rains.

Police said 10 workers were injured in the incident. The injured were rescued and admitted to a local hospital for treatment.

Separately, an 18-year-old youth went missing after the Rapti River in western Nepal's Dang district swept him away.

However, two other men who were stranded in a tree near the swollen river were rescued by security personnel, according to police.

A woman also went missing in Dolakha district, about 180 kilometers east of Kathmandu, after being swept away by a swollen river.

Police have started patrolling on the banks of the river after the water level of rivers in Kathmandu Valley rose alarmingly following incessant rains.

Most places in Bagmati, Gandaki and Lumbini provinces received light to moderate rain, while some places in Bagmati, Koshi, Gandaki and Karnali saw heavy rain.

The flooding of the Hanumante River in Bhaktapur district near Kathmandu, caused by heavy rain, exceeded the danger level and began to penetrate into local residential areas.

More than 600 houses are in danger due to the rising river, police said.

Kathmandu Valley Police Office spokesperson Dinesh Raj Mainali said police have started patrolling to prevent untoward incidents along the river corridors of the Valley.

"We mobilized police teams on the banks of rivers and streams, considering the possible risks of flooding in nearby settlements."

Police vehicles are under constant vigil along the banks of Bagmati, Bishnumati, Manohara and Hanumante rivers, the spokesperson said.