The earth slip entombed the inhabitants of six houses when it hit the village of Ayu in the Osh region of the mountainous Central Asian country at around 6.40 am (0040 GMT), the emergencies ministry said in a statement.
"All 24 citizens of Kyrgyzstan, nine of them children, died under the landslide in the south of the country," ministry spokeswoman Elmira Sheripova told AFP.
Over 250 rescue workers including medics and soldiers were at the scene.
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Emergencies minister Kubatbek Boronov flew to the site on the orders of President Almazbek Atambayev to take "all possible measures to alleviate the consequences of the landslide and give all necessary help to families of the dead", according to a statement on the president's website.
Hours later, a second landslide hit a neighbouring village on Saturday afternoon, burying three houses. There were however no casualties, the ministry said.
In an emotional address published on the presidential YouTube channel, Atambayev pleaded with villagers to heed government warnings to leave their homes during extreme weather in this landslide-prone country.
'Fear God! Listen to experts'
"The biggest pain in all the trouble that has befallen us is [the fact that] two or three days ago our compatriots living there did not listen to the specialists and refused to resettle," said Atambayev, who announced Sunday as a day of national mourning.
"I appeal to my compatriots. A person's life, especially the life of a child, is much more precious than any property, any livestock. You cannot put any sort of property above life!"
He added: "I'm addressing all my compatriots who don't want to leave dangerous zones: Fear God! Listen to the experts and follow their advice."
Prime Minister Sooronbai Jeenbekov visited Ayu village after the landslide and said the government would provide "all necessary assistance".
Watch: Landslide in Kyrgyzstan kills dozens
"We profoundly understand that this is our shared tragedy," he said in comments issued by the government's press service.
The emergencies ministry said its chief Boronov was in charge of organising the evacuation of 40 families living close to the disaster zone and housing them in tents, given the risk of further landslides.
District official Alisher Bakyshev told local media that residents had been ordered to leave by the emergencies ministry in March due to the risk of landslides and 34 families had left their homes - but some later returned.
The landslide is the second tragedy to strike the ex-Soviet country of six million people since the beginning of the year.
In January a Turkish cargo plane crashed into a village close to the country's main airport, killing 39 people.
Ninety-five per cent of Kyrgyzstan's territory is mountainous. A landslide in the country's south in 2004 killed 33 people.
