Almost 5,000 people have been told to evacuate after torrential rain triggered landslides and flooding in Southern Japan.

A further 380,000 people were advised to flee because of heavy downpours in Kumamoto and Nagasaki, on the southern island of Kyushu, officials said.

Evacuations were ordered in Kumamoto after 23 centimetres (nine inches) of rain fell in one day. Nextdoor Nagasaki had 31 centimetres over the same period.

Television footage showed mud and brown water gushing into homes, with hillsides collapsing, blocking roads and damaging houses.

"We have received no reports of injuries," an official said.

Forecasters said the bad weather was expected to continue, with some parts of Kumamoto set to get several more centimetres of rain overnight.

Flooding and landslides that hit the same region in 2012 left more than 30 people dead or missing.

Japan's rainy season is in full swing over much of the country, a month-long period of often ferocious and prolonged downpours.

As a mountainous country with little space available for its 127 million population, landslides in habitable parts of Japan are common, despite the widespread concreting of hillsides in an effort to shore them up.