At least 14 people were killed and dozens more missing after torrential monsoon rains in western Nepal triggered flash floods and landslides, official media reports said.

The government-owned Rising Nepal newspaper said most of the deaths were reported from four districts - Kailali, Kanchanpur, Doti and Gulmi.

In Doti district, about 450 kilometres west of the Nepalese capital Kathmandu, five people included a 7-month-old infant were killed when their house was struck by landslide. .

More than 30 people were reported missing in the four districts while over 20,000 people were displaced from their home.

The entire Kailali district was under water and over 350 houses were swept away by floods, the newspaper quoted government officials in the district as saying.

The floods had also damaged road and telecommunication links hampering rescue efforts and determining the extent of damage, the newspaper said.

The floods inundated dozens of villages in western Nepal and many people were awaiting rescue by climbing onto tree tops, the newspaper said.

Rescue officials said the actual toll could be much higher and the full extent of the damage can only be ascertained after the rains stopped and water levels receded.

The flooding and landslides were caused by torrential monsoon rains which began from Friday evening.

The country's meteorological department in its report said some areas in western Nepal had received as much as 345 millimetres of rain in just 24-hour period.

The department said it expected the rains to continue till Sunday night.

Although monsoon has been relatively weak this year, at least 70 people have died in flooding and landslides across the Himalayan nation since June.

Nepal receives nearly 80 per cent of its total annual rainfall during four months long monsoon season that last from June to late September.