Tokyo (CNN) -- Exceptionally heavy rains have killed at least 19 people and flooded hundreds of houses on the southern Japanese island of Kyushu, the local authorities said Friday.
The intense rainfall in certain areas of the prefectures of Kumamoto and Oita has attained levels "never experienced before," the Japan Meteorological Agency said.
In one part of Kumamoto, the equivalent of one month's rain fell in the space of just eight hours early Thursday, according to the meteorological agency.
Besides the 19 people who died -- some of them in landslides and houses that collapsed -- eight people are missing, according to information posted on the websites of the local prefecture offices and fire services.
The violent rain has damaged 75 houses and flooded more than 500 in the two prefectures, the local authorities said.
Evacuation orders were temporarily issued for tens of thousands of households as the Shirakawa River, which runs through Kumamoto City, began spilling over its banks. Helicopters plucked some residents from the roofs of their homes. Most of the evacuation orders had been lifted by Friday morning.
Kyushu is the third largest island of Japan, located southwest of the main island, Honshu.