Nepal suffers flash floods and landslides during the June-September rainy season, resulting in loss of life and property every year.
A massive landslide swept away dozens of houses, killing at least 10 people, early on Friday in Sindhupalshowk, near the capital Kathmandu, ministry official Murari Wasti said.
He said 28 people were missing.
“Rescue work has been hampered by continuous rain and mud still falling from the hills,” Wasti told Reuters.
Six people, aged between 10 and 19, were killed in remote Kalikot in far west Nepal - four of them from the same family.
Floods and landslides have so far killed 215 people this year, while 85 are missing, according to official data.
Dibya Raj Poudel, of the Nepal Red Cross Society, said 40,000 people had been housed in temporary huts or were staying with relatives or friends.