Story highlights Dozens missing after torrential rainfall in Japan's southwest

More than 7,800 rescuers are searching for missing and stranded people

Japan (CNN) At least 18 people were killed and hundreds are still stranded after heavy rains triggered floods and landslides this week in southwest Japan, according to Japanese state-run NHK news agency.

Fifteen people died in Fukuoka and three in Oita Prefecture. An evacuation order remains in effect for nearly 105,000 people.

Heavy rains hamper search efforts

Aerial television footage shows how rivers overflowing with water ripped through swathes of land, toppling houses and sweeping away roads.

Collapsed houses are half-buried in mud following the flooding caused by heavy rain in Asakura, Fukuoka prefecture, southwestern Japan.

More than 7,800 rescuers from the Fukuoka police force and Japan self defense forces have been working around the clock to search for missing people. But heavy rain Friday hampered their efforts, making rescue operations treacherous as they battled against thick mud and debris.

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