TOKYO - A powerful typhoon approached Japan's main islands Wednesday, closing car factories, disrupting flights and threatening heavily populated industrial centers with torrential rain and strong winds.

Typhoon Melor may be the most powerful storm to hit Japan's main islands in more than 10 years, the Meteorological Agency said, prompting media reports recalling a deadly 2004 storm that killed 95 people and brought transport links to a standstill.

The eye of the storm was 280 km (173 miles) south of Cape Ashizuri, 700km west of Tokyo, at 4 p.m. (0700 GMT), the Meteorological Agency reported.

Television showed waves pounding the shores as the typhoon moved north-northeast toward the main island of Honshu. It is expected to make landfall southwest of Tokyo Thursday.

Up to 500 mm (20 inches) of rain is forecast over the next 24 hours in the Tokai region, which includes the industrial center of Nagoya, said the agency, which also warned of high waves and gales in southern, western and eastern Japan.

Some municipal offices in Tokyo distributed sandbags and Japanese media reported 220 flights had been canceled.

Toyota Motor Corp said it would stop production in all 12 of its Japanese car plants for a day because of the storm.

Chief Cabinet Secretary Hirofumi Hirano said there could be landslides and floods.

I would like for those in relevant areas to remain cautious and... to respond quickly, he told a news conference.

The storm cut power to around 4,300 customers in southern Japan, Kyushu Electric Power Co said.

Some oil firms halted shipments although the storm has not so far affected refinery production.

Nippon Oil Corp said it had halted marine oil product shipments at its Mizushima and Osaka refineries in western Japan Wednesday afternoon.

Idemitsu Kosan Co said it has halted marine oil shipments at its Tokuyama and Aichi refineries Wednesday afternoon. Overland oil shipments have been also put on hold at the Tokuyama refinery, a company spokeswoman said.

Japan Energy Corp, the nation's sixth-biggest oil refiner, said it would halt overland oil shipments from its Mizushima refinery in western Japan during the night hours. Nansei Sekiyu KK's refinery in Okinawa said high seas were delaying some ships.

Melor, which had earlier been classed as a Category 5 Super Typhoon, has been downgraded to Category 2, according to storm tracking Website Tropical Storm Risk. A Category 2 storm can bring winds of up to 177 kph (110 mph).

Heavy rainfall has disrupted much of the Japan Open men's tennis tournament in Tokyo and the typhoon could force the postponement of Thursday's soccer Asian Cup qualifier against Hong Kong.

An average of about three such storms hit Japan each year, although there were none last year.

(Additional reporting by Isabel Reynolds, Osamu Tsukimori, Yoko Nishikawa and Mayumi Negishi; Editing by Hugh Lawson)

Down Japan