Most cities and counties declared a day off work and school though the island's capital, Taipei, home to financial markets, was not affected and was operating as normal.

Scientists warn that typhoons hitting China are becoming more intense and their paths growing more complex, escalating risk of disaster.

Haikui made landfall in the mountainous and sparsely populated far southeast of Taiwan, the first typhoon to directly hit Taiwan in four years.

The military has mobilised soldiers and equipment to help with flood relief and evacuation efforts.

Saola is packing winds of more than 200kph and will move towards the coast of eastern Guangdong, the neighbouring province on the Chinese mainland.

Taiwan has issued land and sea warnings for the storm, with ferry services and flights to several offshore islands and the southeastern city of Taitung cancelled.

The typhoon, which followed closely on the heels of Typhoon Khanun during Japan's peak Obon holiday season, lashed wide swathes of central and western Japan with heavy rain and powerful winds.

Hebei, part of the Haihe River basin, northern China’s largest, was lashed by more than a year's rainfall, forcing the evacuation of more than 1.6 million people.

South Korea issued its highest alert as Khanun forced the cancellation of nearly 80 flights and the closure of dozens of sea routes and roads, reports say.

Hebei province was struck by more than a year's rainfall from storms that followed Typhoon Doksuri, affecting autumn crops and damaging agricultural equipment.

The storm is currently in the sea south of Kyushu after wreaking havoc in the southwestern Okinawa region.

After skirting western parts of Japan's Nagasaki prefecture, Khanun is projected to make its way parallel to the coast north toward South Korea, reports say.