TAIPEI/BEIJING (REUTERS) - Taiwan issued a warning to ships and airlines cancelled some flights on Wednesday (Sept 13) as the island braced for Typhoon Talim, which was expected to hit cities including the capital Taipei, before hurtling towards China potentially as a super typhoon.

Talim was expected to gain in strength as it sweeps towards Taiwan's northern cities, lashing them with strong wind and heavy rain, the Central Weather Bureau said.

The brunt of the storm would be felt later on Wednesday and on Thursday, when it was expected to slam into the north and north-east with maximum sustained wind speeds of 137 kmh and gusts of up to 173kmh, according to the bureau's website.

"Typhoon Talim has been changing its course and is not entirely predictable. It's been expected to hit Taiwan directly, but its trajectory has altered further northward and eastward," said Taiwan's Premier William Lai. "But at this point our emergency operation centre has not lowered its level of alert," the premier added.

It had not yet been determined whether the Taiwan government would close financial markets, companies or schools on Thursday. An announcement would be made later on Wednesday if closures were considered necessary.

China Airlines and EVA Airways, Taiwan's two largest carriers, said they would cancel some inbound and outbound international flights scheduled for later on Wednesday. A warning for sea traffic was also issued by the Central Weather Bureau.

Formosa Petrochemical Corp, Taiwan's second-biggest oil supplier, said it had prepared to close its supply port if necessary, although it was waiting for a government directive.

Typhoons are a seasonal routine for Taiwan, but the island has enhanced its preparations and been on guard against the potential for severe and deadly storms since Typhoon Morakat devastated the island in 2009.

Morakat was the deadliest typhoon to hit the island in recorded history, killing close to 700 people, most of them in landslides.

MAINLAND ON ALERT

In mainland China, more than 200,000 people in Fujian and Zhejiang provinces have been evacuated, China's official Xinhua news agency said.

As early as Thursday night, Talim could make landfall along the northern coast of Zhejiang province on the Chinese mainland as a strong typhoon, packing gusts of up to 48 metres per hour, China Meteorological Administration said in a statement on Wednesday.

The agency maintained an orange warning on Wednesday - the second-highest in a four-tier colour-coded system for severe weather.

Throughout Wednesday and Thursday, strong winds and rain are expected to buffet the coastal areas of Zhejiang and Fujian as well as the East China Sea and Taiwan Strait, the mainland's weather agency said.

Talim could strengthen into a super typhoon with winds of 52 metres per second in the late afternoon on Thursday just before making landfall in Zhejiang.

Zhejiang authorities have told fishing vessels to seek shelter by Wednesday. A fishing ban will be in place until Friday.

The railway bureau in Shanghai, north of Zhejiang, said it had stopped selling tickets for hundreds of trains over the next few days.

The storm is expected to turn north-east towards Japan on Friday, while another heads toward southern China and Vietnam.

Tropical Storm Doksuri is expected to steadily intensify and become a strong typhoon and brush past the southern coast of Hainan province in the evening on Thursday or early Friday.

In face of incoming twin typhoons, provinces in their way have been on high alert for heavy rainfall, storm surges, flash floods and landslides.

As many as half a million people may need to be evacuated if the storm intensifies, according to Chinese media reports.

Fujian said more than 20,000 people had been evacuated by 7am local time on Wednesday. Provincial authorities have also shut some coastal scenic spots and suspended thousands of ships and ferries.

The Fujian meteorological agency said it would maintain its yellow alert for Talim, the second-lowest in the four-tier warning system.

Hainan has suspended all trains in and out of the island province over the next few days. Ships and offshore workers have been told to seek shelter.

Cathay Pacific Airways said on Wednesday that flights to and from Sanya, the southernmost city on Hainan island, may be affected on Friday.

Doksuri, known as Maring in the Philippines, had dumped heavy rain on the Philippine capital of Manila and nearby provinces earlier this week, causing widespread flooding and landslides.