The Observatory said it would consider issuing the Strong Monsoon Signal depending on the progress of Super Typhoon Gaemi, which is forecast to move across Taiwan and make landfall over Fujian later on Thursday.

It said on its website that Gaemi is expected to stay about 600km from Hong Kong before making landfall over Fujian.

The Observatory warned that Gaemi will bring strong offshore winds to Hong Kong later on Thursday and early on Friday, along with temperatures of up to 35 degrees or more in parts of the territory.

Gaemi made landfall overnight in eastern Taiwan's Yilan County.

Officials said two people are dead and 201 injured. It's forced the suspension of high-speed railway service, and the cancellation of hundreds of flights.

Classes and business operations in 22 counties and cities have been suspended.

Earlier, Gaemi exacerbated seasonal rains in the Philippines, triggering flooding and landslides that killed six.

The first typhoon to make landfall in Taiwan this year, Gaemi was "expected to be the strongest" one in eight years, a government forecaster told AFP.

It had caused downpours and strong gusts across Taiwan before its arrival, killing one motorist in southern Kaohsiung city who was crushed by a falling tree, and a woman in eastern Hualien, authorities said.

More than 200 people were injured by Wednesday evening, while more than 290,000 homes were plunged into darkness due to power outages, disaster officials said.

By 8pm (1200 GMT) on Wednesday, authorities had evacuated more than 8,000 people living in precarious conditions across Taiwan, particularly in Hualien -- a mountainous area with a high risk of landslides.

Trains and ferry services were suspended and hundreds of international and domestic flights were cancelled on Wednesday.

"We expect that the impact of the typhoon will be extended to four days (until Friday)," said Taiwan's Central Weather Administration chief Cheng Jia-ping.

Schools and offices will remain closed for the second day in a row in several cities -- including Taipei -- with authorities expecting adverse weather to continue across the island.

Gaemi is expected to make its way across the strait on Thursday and hit eastern Zhejiang and Fujian provinces, where authorities have issued a red storm alert.

Earlier, Gaemi swept past the Philippines, intensifying monsoons that were typical this time of the year and triggering widespread flooding in Manila that turned streets into rivers.

Landslides killed six in provinces surrounding Manila, police and disaster officials said.

Weather authorities in Japan's southern island region of Okinawa urged residents to "exercise strong vigilance" against storms, high waves and floods. (Additional reporting by AFP)