At least 16 people have died and dozens more are missing after landslides triggered by heavy rains swept away two villages in quake-hit Nepal.

Rescuers are searching through rubble for around 32 people believed missing in the western district of Kaski in the foothills of the Himalayas, around 150 kilometres west of Kathmandu.

"At least 16 people are dead in two different landslides in the district due to heavy rainfall last night," Kaski police chief Kedar Rajaure said on Thursday.

"The rescue operation is on. We are trying to find missing people."

Eighteen people injured in the disaster have been taken to local hospitals for treatment, he said.

Scores of people die every year from flooding and landslides during the monsoon season in Nepal.

Two weeks ago a student was killed when a landslide buried part of a school in the nearby town of Pokhara, and 35 people died last month when a landslide crushed villages in northeast Nepal.

The monsoon rains are also hampering delivery of relief supplies to mountainous villages devastated by the massive earthquake that struck the Himalayan nation on April 25.

More than 8800 people were killed by the quake and a large aftershock, and many more were left without shelter.