|Thousands of people have been forced to flee their homes due to the risk of floods [Reuters]
Typhoon Nanmadol has slammed into Taiwan, closing schools, workplaces and government offices.
It has dumped more than half a meter of rain in the mountainous south, where vulnerability to catastrophic landslides prompted the evacuation of some 8,000 people.
Nanmadol made landfall just before daybreak Monday in Taidung county in the remote southeast and headed toward heavily populated coastal areas on the west coast. It is now packing winds of 108kph, down from earlier peaks almost twice that high.
It is expected to pass about 200km south of Taipei before heading for the Taiwan Strait and the eastern China coast.
Steff Gaulter, Al Jazeera's senior meteorologist, said the main problems will be caused by excessive rain, rather than the strength of the wind.
"After the recent torrential rains on the island, the ground is saturated and this, combined with the mountainous terrain, could easily trigger deadly mudslides.
"So, although it is forecast to disintegrate quickly in about 12 hours time, it could easily change track or change intensity without warning."
As of 10 am (0200 GMT), many domestic flights had been canceled, and officials with Taiwan's high speed rail network, which serves heavily populated areas along the west coast, were weighing a suspension of services.
According to the website of Taipei's main international airport, almost all overseas flights were operating normally.
Nanmadol has killed at least 12 people in the Philippines and left another nine people missing.
Taiwan evacuated 2,500 villagers of the 3,700 people it plans to evacuate from the east and south of the island, the Central Emergency Centre said on Sunday.
Authorities urged the public to stay away from mountainous and low-lying areas while the defence ministry ordered 35,000 soldiers in the east to be on stand by.