A powerful typhoon has hit Taiwan, killing at least four people and injuring nearly 30 others.

Torrential rain and strong winds of up to 230km/h battered the island, with winds up to 140km/h reported in the capital Taipei.

Millions of homes and businesses have been left without electricity as a result of the storm.

BBC reports that schools and offices have been closed, while flights and train services have been cancelled.

An eight-year-girl and her mother died when they were swept out to sea from a beach, the government's Central News Agency said.

Other casualties include a firefighter who was killed after being hit by a motorist as he attempted to move a fallen tree, the news agency said.

The typhoon triggered a landslide in one northern village, with a representative of Taoyuan fire agency telling AFP that "flash mudslides surged into the village. About 10 of the homes were half buried but people were evacuated last night and are in safe shelters."

Taiwan's Central Weather Bureau warned that mountain areas should be on alert for landslides and low-lying areas for flooding.

Areas of mainland China are now on high alert for Typhoon Soudelor, which is forecast to hit there tonight. More than 150,000 people have been evacuated in the province of Fujian ahead of the typhoon making landfall.