KATHMANDU: At least 15 people have been killed and others have gone missing due to landslides and floods as monsoon rains lashed Nepal, the government said on Friday.

Heavy rains since Thursday have hit 20 of Nepal's 77 districts in the hills as well as the southern plains.

A Home Ministry statement said 15 people had been killed, while six others were missing and 13 were injured as incessant rains caused landslides and triggered flash floods in rivers originating in the Himalayas.

In the capital, Kathmandu, three members of a family were killed when the wall of their house collapsed.

Television channels showed police evacuating residents from flooded homes in rubber boats in some parts of Kathmandu where roads were flooded. Families carrying their belongings on their heads waded through waist-deep water.

"We have evacuated more than 150 people and are on standby for rescue in different areas," Army spokesperson Bigyan Dev Pandey said.

Officials said the Koshi River in eastern Nepal, which flows into the eastern Indian state of Bihar, had risen above the danger mark.

The weather office asked residents to remain alert saying heavy rains were expected to continue through the weekend.

The annual monsoon rains, which normally start in June and continue through September, often result in casualties in Nepal, a country of 30 million people.