Updated

Taiwan braced for the arrival of Typhoon Soulik, which is expected to pound the island with powerful winds and heavy rain over the weekend despite the giant storm losing strength.

Offices and schools will be shut down in Taipei and four other cities later Friday, with people advised to avoid sea and outdoor activities as the typhoon churns towards the island.

Taiwan's Central Weather Bureau downgraded Soulik from a super typhoon to a moderate typhoon but warned residents across the island to prepare for torrential rain and rough seas.

As of 0030 GMT Friday, Soulik was 470 kilometres (292 miles) east of Ilan county on the northeastern coast.

With a radius of 280 kilometres and packing winds of up to 173 kilometres an hour, the typhoon was moving west-northwest at 23 kilometres per hour.

The bureau predicted that the impact of Soulik will be strongest early Saturday but it is less likely to regain the momentum of a super-typhoon as it nears land.

It could narrowly miss the island or make landfall in Yilan or Hualien counties on the northeast coast around 3am Saturday (1900 GMT Friday), the bureau said.

The storm has disrupted travel to and from Taiwan. In a statement, airline Cathay Pacific said the majority of its flights between Hong Kong and Taipei from late Friday evening to Saturday afternoon will be cancelled.

Taiwan's China Airlines also said it had cancelled some flights, while EVA Airways said it would operate a normal schedule Friday before reviewing Saturday operations according to the typhoon's development.

More than 2,000 tourists were evacuated on Thursday in preparation for Soulik, while Japan's Okinawa warned residents that giant waves of up to 12 metres (40 feet) could pound the archipelago.

A water festival in Yilan will be shut down over the weekend while several pop music concerns have been postponed due to safety concerns, organisers said.

Soulik was moving along the same route as 1996 super-typhoon Herb, which left 51 dead and 22 missing, although it is moving faster, according to the weather bureau.

In August 2009 Typhoon Morakot killed about 600 people in Taiwan, most of them buried in huge landslides in the south, in one of the worst natural disasters to hit the island in recent years.