Heavy monsoon rains and landslides have killed almost 50 people in Nepal and India in recent days, authorities said on Sunday.

In western Nepal at least 22 people died after landslides buried more than 100 houses on Friday, police official Narayan Dangi told AFP.

Eleven people were injured, including three airlifted to hospital by army helicopter.

"Rescue teams are still searching for one missing person," Dangi said.

A major relief operation was underway with the police and army clearing debris and distributing food, tents and clothes.

Over the border in the northern Indian state of Uttar Pradesh, heavy rains have killed 26 people since Friday, officials said.

The fatalities included nine labourers buried alive when a wall under construction in the state capital Lucknow collapsed on their huts, according to a government statement.

The annual monsoon brings South Asia 70-80 percent of its annual rain but it also brings death and destruction, with nearly 1,400 people killed in Pakistan in recent weeks.

The rainfall is hard to forecast and varies considerably, but scientists believe that climate change is making the monsoon stronger and more erratic.