TOKYO -- Heavy rain triggered flash floods and mudslides in southern Japan on Thursday, causing at least 15 deaths and leaving 11 more people missing.

Television footage showed residents wading through muddy, knee-deep water on streets. Others shoveled out mud from their homes.

Local officials said damage was concentrated in Kumamoto and neighboring Oita states on Japan's southern island of Kyushu. Most victims were in their 70s and 80s.

Hundreds of homes were destroyed or damaged, and tens of thousands of people had to evacuate the area threatened by swollen rivers and mudslides.

The Meteorological Agency said as much as 50 centimeters (20 inches) of rain fell overnight. It predicted up to 20 centimeters (8 inches) of rainfall through Friday.

Rescue workers and defense troops have been sent to the region to help. Some residents trapped in inundated areas were airlifted by helicopters.

The heavy rains also disrupted local train services, blocked off roads and left about 22,000 homes without electricity.

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  • A road is covered with mud and woods carried by a mudslide in Aso, Kumamoto Prefecture, western Japan, Thursday, July 12, 2012. (AP Photo/Kyodo News)

  • In this aerial photo, a house along flooded River Kagetsu is destroyed by floodwater in Hita city, Oita Prefecture, southern Japan, because of torrential rain. (AP Photo/Kyodo News)

  • In this aerial photo, houses along flooded River Kagetsu are destroyed by floodwater in Hita city, Oita Prefecture, southern Japan, because of torrential rain. (AP Photo/Kyodo News)

  • In this aerial photo, River Kagetsu is flooded in Hita city, Oita Prefecture, southern Japan, because of torrential rain. (AP Photo/Kyodo News)