Tropical Storm Saola, previously a typhoon, has killed at least five people and injured 15 others as it triggered landslides and flooding across Taiwan.

The storm caused nearly the entire island to close down, as official said torrential rains could linger until next week.

The typhoon arrived in Taiwan early on Thursday, a day after the storm killed 23 people and forced 154,000 from their homes in the Philippines.

The Taiwanese military helped more than 1,000 people flee from the remote mountainous north and east of the island.

The National Fire Agency reported five deaths, including a policeman who drowned in a swollen river. Two people were missing.

More than 100 domestic and international flights were cancelled, train services disrupted and roads closed.

While some major companies remained open, Taiwanese authorities ordered other businesses and schools to shut.

Financial markets were also shut, with normal operations expected to resume on Friday.

Saola has weakened significantly in the last 24 hours due to its interaction with Taiwan's rugged terrain.

Chinese alert

A separate system, Typhoon Damrey, is expected to pass north of China's financial hub of Shanghai on Friday but will weaken to a tropical storm.

Typhoon Saola has killed 23 people in the Philippines, while displacing 157,000 people [AFP]

China's meteorological agency issued typhoon warnings on Thursday for the southern and eastern provinces of Fujian and Jiangsu.

On Tuesday, China's Premier Wen Jiabao told authorities to be on the highest alert.

Wen, who usually leaves more junior leaders to oversee arrangements before storms, told authorities to step up preparations and "put people's lives first", the official Xinhua news agency said.

Forecasters also predict rain through to Friday, and warn of possible landslides and road collapses.

Saola is named after the rare mammal found in Laos and Vietnam.