A typhoon lashed south-western Japan on Monday, creating nine-metre high waves, cutting power supplies and disrupting transport and work at oil refineries. Weather officials in South Korea also warned of flooding, while eastern China braced for possible effects from Typhoon Nabi after another storm last week killed at least 84 people in the east of the country, newspapers said.
Nabi was 150 km (94 miles) south-west of the tiny southern Japanese island of Yakushima at 6 pm (0900 GMT), the Meteorological Agency said. Winds were gusting up to 160 kph (100 mph) at the centre of the typhoon, but the storm weakened slightly as it passed over cooler water.
The Tropical Storm Risk Web site had classified Nabi as a Category 4 storm on an ascending scale of 1 to 5, the same category as Katrina, which hit the US Gulf Coast last week. But later on Monday, it downgraded the storm to a Category 3.
Typhoon Nabi, whose name means "butterfly" in Korean, was travelling north-north-west at 15 kph (10 mph), heading directly for the densely populated southern island of Kyushu.
The Meteorological Agency expects Nabi to swerve to the east over the next 24 hours, putting it on course to batter much of Japan and southern and eastern parts of South Korea.
Television pictures showed coastal areas of Amami Oshima being engulfed by waves that national broadcaster NHK said were up to nine metres high.
At least four people were injured on Kyushu as the storm approached the island, police said.
Japan's top government spokesman, Hiroyuki Hosoda, said the country's military, police, fire-fighters and coast guard were on standby.
Hundreds of flights in and out of Kyushu were cancelled on Monday, NHK said. Trains were also cancelled and expressways closed in southern parts of the island. Nearly 20,000 households were without electricity on Kyushu, NHK said.
South Korean airlines have cancelled about two dozen domestic flights to its southern cities due to high winds and airline officials said the number of cancellations would likely increase as the typhoon draws near.
South Korean weathermen said the worst of the typhoon would hit from about Tuesday afternoon.
Nabi has sparked thunderstorms in Tokyo, where more than 110 mm (4.3 inches) of rain fell in an hour in some areas late on Sunday. Two men were killed - one drowned and one was struck by lightning - in areas close to the capital, police said.
Thousands of households in or near Tokyo were flooded and lost power, while some highways were closed and trains delayed.
Japanese oil refiners suspended waterborne operations at some of their facilities on Monday, refinery spokesmen said.