Ten more people were missing and the number of dead looked set to climb as large parts of the country were under water, officials said.
“As a result of floods and landslides caused by heavy rains that poured in the last 24 hours, in Nepal killed more than 30 people”, – stated in the message.
Landslides and floods are common in Nepal during the monsoon season and the rest of the region.
In the eastern city of Biratnagar an airport runway was under two feet of water, TV footage showed, leading to a suspension of flights.
Four people were killed in Sindhuli, four in Banke and one person each in Morang and Jhapa districts, The Himalayan Times reported.
According to the Ministry of Home Affairs, seven persons were killed in Sunsari district in southern Nepal.
Six bodies were fished out from the swollen streams in Sunsari while hundreds of families were displaced, he added.
Prime Minister Sher Bahadur Deuba has instructed administrators in flood-hit districts to expedite rescue and relief efforts. Officials say most areas in Jhapa, Morang, Sunsari, Sarlahi and Rautahat have been inundated.
Nepalese Home Minister Janardan Sharma said that all the security agencies will be mobilised in an integrated manner for carrying out the rescue operations.
Hundreds of houses have been submerged in Morang.