People look at damaged buildings after a tornado struck Tsukuba city, northeast of Tokyo / Pic: AP Source: The Daily Telegraph

This photo taken by an anonymous Tsukuba resident shows a tornado in Tsukuba city, northeast of Tokyo. Source: The Daily Telegraph

Firefighters and medical teams rushed to Tsukuba city, a science centre near Tokyo, but the tornado appeared to have struck mostly in residential areas.

The dead boy was among 12 people rushed to hospitals by rescue workers. A city official said another 15 people sought medical care for tornado-related injuries – but “the figure is only a temporary tally … we believe the number (of injuries) could rise.”

The Tsukuba fire and emergency bureau said 30-50 houses were completely destroyed by the tornado, with hundreds damaged.

A number of minor injuries were also reported in neighbouring Tochigi prefecture, and a swath of eastern Japan was battered by strong winds, hail, lightning and heavy rain.

Television footage from Tsukuba 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 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.

Japan’s weather agency issued 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 also caused a power outage for more than 20,000 households in the region, a spokeswoman for Tokyo Electric Power said.

Fukushima Dai-ichi nuclear power plant, which went into multiple meltdowns from last year’s tsunami, was not affected by the tornado or subsequent rain, TEPCO added.

Tornadoes are relatively rare in the Tokyo area.