A tornado ripped through eastern Japan, injuring at least 20 people, destroying houses and cutting power to around 20,000 households.
There were no immediate reports of fatalities after the twister hit Tsukuba city in Ibaraki prefecture, according to a duty officer at the city's fire and emergency bureau.
"We have information that roughly 20 people were injured," he said.
"We have reports that 30 to 50 houses were destroyed by the tornado."
Local media reported at least 30 injuries.
Television footage from Tsukuba, roughly 60 kilometres north-east of Tokyo, showed houses swept from their foundations, overturned cars in muddy debris and fallen concrete power poles.
Aerial images showed possibly hundreds of houses and apartments with shattered glass windows, many of them with their roofs blown away.
"You could see the roaring column of wind rushing with sparks from live power lines inside it," a local man told national broadcaster NHK.
"Winds blew into my house. It took only a moment," a woman told NHK while cleaning up her home.
Japan's weather agency issued tornado warnings for a wide region in the east of the country, urging people to seek shelter in case of sudden winds and thunder.
The severe winds caused a power outage for nearly 20,000 households in the region, said a spokeswoman for Tokyo Electric Power.
"The tornado and thunder happening around 12:46 pm (0346 GMT) are believed to be the cause of the outage for 19,300 clients in Tsukuba and its surrounding areas," she said.