A super-strength typhoon that brought flooding to parts of the Philippines tore into Taiwan on Friday, forcing the cancellation of flights and sending coastal residents rushing to secure their homes.

Waves swelled, winds picked up and rain battered the north of the island as Typhoon Sepat began its landfall, a disaster relief official and local media said. All cities and counties ordered work and classes to stop on Saturday.

"There's already a huge wind, and waves hitting the coast pose a danger," said Fei Yu, a resident of coastal Taitung County. "Most people living here are making preparations at home to ride out the storm."

Local TV channels showed fallen sign boards, including one that blocked a busy street, other damage, and wind strong enough to make walking a struggle.

Taiwan's Civil Aeronautics Administration said 33 domestic flights had been cancelled as of mid-afternoon on Friday. International airports serving Taipei, Kaohsiung and Taichung also grounded southbound international flights to destinations such as Hong Kong and Southeast Asia.

Train service on eight routes had also been suspended around the island through early Saturday.

Sepat will probably smack into the cities of Kaohsiung and Taichung, both with populations of more than 1 million, after the centre of the storm hits land around 2300 GMT on Friday, and then pummel the Chinese coast, according to Tropical Storm Risk (www.tropicalstormrisk.com).

The centre of the category 5 typhoon was 260 km (99 miles) off the coast of Taiwan as of 1400 GMT, packing sustained winds of 184 kph (114 mph) and gusts up to 227 kph (141 mph).

But the storm will weaken by the time it reaches major Taiwan population centres and China because the mountains of central Taiwan will weaken its force, a disaster official said.

Up to 1,000 millilitres of rain were forecast for parts of the island, Taiwan TV reported.

China's southeastern province of Fujian was bracing for the typhoon to make landfall on Saturday evening or Sunday morning local time, the official Xinhua news agency said.

Typhoons draw strength from warm waters of the South Pacific and South China Sea, regularly targeting the Philippines, Japan, China, Taiwan and Hong Kong over the summer, sometimes with catastrophic effect.

In the Philippines, rains exacerbated by Typhoon Sepat continued to soak Manila and surrounding provinces on Friday after the cyclone brought the capital to a near standstill two days earlier, with major roads in the vicinity under water up to 5 feet (1.5 metres) deep in places.

Schools remained shut in Manila and the northern Philippines, while the government suspended work in public offices from 0500 GMT to let employees get home before flooding cut off roads.

Some areas of the city were already submerged in waist-deep water. Power failed in parts of the capital due to the strong winds and rains. In neighbouring Rizal province, authorities urged residents in landslide-prone areas to evacuate their homes.

Also on Friday, local airlines Asian Spirit and Cebu Pacific cancelled flights around the Philippines.