A powerful typhoon has struck Japan, bringing torrential rains and floods that have killed five people.
Typhoon Roke is now closing in on Fukushima, where engineers are still struggling to bring a nuclear plant under control after the March tsunami.
There are concerns heavy rain could force radioactive water into the sea
The storm, packing winds of 162km/h (100mph), passed near Tokyo stranding tens of thousands of commuters as trains and flights were cancelled.
The typhoon made landfall on Wednesday afternoon (05:00GMT) in Hamamatsu, scouring its way up the main island of Honshu.
The storm is now tracking a path towards Fukushima prefecture and is then expected to travel up along the north-east coast, which was battered by the 11 March earthquake and tsunami.
The BBC's Roland Buerk in Tokyo says pools of radioactive water remain at the Fukushima nuclear site, and there is concern that a heavy downpour could cause them to overflow into the sea or groundwater.
A spokesman for Tepco said the firm was taking "every possible measure against the typhoon".
"We have tied down cables and hoses while fixing equipment so that radioactive materials will not spread [in violent winds]," said Naoki Tsunoda.
He said the work on the ground and at sea had been suspended.Caution urged
Five people have so far been found dead in central and western Japan, public broadcaster NHK reported.
Four people are missing including a nine-year-old boy and 84-year-old man who were swept away by flood waters in Gifu prefecture as the storm approached.
At least 55 people have been injured, NHK said, and nearly 260,000 households in central Japan are without electricity.
Evacuation advisories remain in place for around 330,000 people nationwide.
Yokosuka resident Atsuhiko A-chan Hayasaka said strong winds were battering his house.
"It feels like we will be blown outside. The wind is much more severe than the downpours now. My house is shaking every time the strong winds hit.
"Fortunately we have no blackout, so we will be eating dinner using the electricity as usual. But I am concerned because according to TV reports the typhoon is expected to reach near here," he told the BBC.
Car maker Toyota has suspended production at 11 of its 15 factories.
Japan's Meteorological Agency has urged "the highest level of caution be used because of the heavy rain, strong wind, and high waves."
The agency has warned of downpours over a wide area of the country on Wednesday, saying some places could be deluged by as much as 50mm of rain in an hour.
This is the second time in less than a month that Japan is being lashed by a typhoon. Talas ripped through the west of the country, leaving about 90 people dead or missing.