Even while the storm was still out at sea, its gusting winds of up to 227 kilometres (136 miles) per hour wreaked havoc across Taiwan as the government warned of possible flash floods and landslides.

The centre of the typhoon was situated about 50 kilometres (30 miles) south of the eastern coastal city of Hualien at around 0400 GMT. It was expected to make landfall within hours before heading towards the coast of mainland China overnight.

"Haitang is the most powerful typhoon to hit Taiwan over the past five years. Residents must be vigilant," said a spokesman for the Central Weather Bureau.

A spokesman for the Civil Aeronautics Administration told AFP 110 international flights from Chiang Kai-shek airport in the north of the island were cancelled. Up to 400 domestic flights were also cancelled.

Television footage showed giant waves whipped up by the typhoon pounding the shore of Hualien. Flooding also threatened Yihsin Village in the northern county of Hsinchu, forcing the evacuation of residents.

Around 750 people in northern Taiwan were evacuated from remote mountainous villages by local governments and placed in temporary shelters, said the National Fire Agency. Officials said 34 people had been injured around the island in typhoon-related incidents.

In the capital Taipei anxious residents piled sandbags around their houses as they braced for the typhoon, while thousands of fishing vessels sought shelter in harbours.

Some 4,800 mainland Chinese fisherman took shelter in Taiwanese ports.

The typhoon knocked out power supplies to over 38,000 households, largely in the eastern and northern part of the island.

The management of the 508-meter (1,676 feet) Taipei 101, the world's tallest skyscraper, put staff on alert as the building was expected to face its most powerful typhoon since it was inaugurated in December 2004.

But Hsieh Wen, spokesman for the Taipei Financial Center Corporation which owns the building, told AFP that he was confident Taipei 101 was "designed to resist the most powerful winds ever reported."

The building is armed with a wind damper on the 88th floor, a 680 tonne steel ball designed to reduce the impact of strong winds.

Workers piled sandbags around the building's doors and entry to the underground parking lots, and glued tape on windows to ensure that people in the building would not be hurt by flying glass should windows be broken by debris.

Chinese Premier Wen Jiabao urged the authorities in the southeastern province of Fujian, which faces Taiwan, to prepare for the impact of the typhoon.

The provincial meteorological station of Fujian said gales swept over coastal areas of the province Monday and that the full force of the typhoon was expected to hit on Tuesday between the cities of Quanzhou and Ningde.