TOKYO: Rescuers were racing against time on Friday in the search for people buried under mudslides as heavy rains that have already claimed 20 lives continued to pound southwestern Japan.

Police, firefighters and troops were digging through mud and rubble with shovels as more torrential rain fell, on top of “unprecedented” downpours that swamped whole neighbourhoods on Thursday.

Television footage showed torrents of muddy water carrying uprooted trees and other debris after Thursday's violent deluge, while rivers burst their banks and flooded towns and villages in the main southern island of Kyushu.

Reports showed residential streets in the city of Kumamoto covered in mud, while battered cars that had been swept away by flood water were left dumped on hillsides in scenes reminiscent of the March 2011 tsunami in the northeast.

In the city of Aso in Kumamoto prefecture, central Kyushu island, landslides buried at least 17 households, killing 19 people with six more still missing, local officials said.

“We will keep searching for the missing throughout the night, while urging our citizens to stand guard as heavy rain continues sporadically,” said Kumamoto prefectural official Yushin Maekawa.

In Oita, a man in his 70s died after being swept into a raging river, while another man remained missing.

Public broadcaster NHK showed rescuers continuing their search, using heavy machinery to remove uprooted trees, boulders and debris as night fell.

The weather eased somewhat Friday morning bringing temporary relief, but further downpours were recorded in Kyushu later in the day.—AFP