The Central Weather Bureau urged the public to be vigilant as the storm, 210 kilometres (130 miles) east of Taipei at 0330 GMT, was likely to introduce "cloudbursts" -- more than 100 mm of rain per hour -- in some areas.

Persistent torrential rains could lead to landslides in mountainous areas and flooding, it warned.

The storm, with gusts up to 137 kilometres per hour, was moving west north-west at a speed of 25 kilometres per hour, the bureau said.

Officials at the bureau said the impact may be felt mostly from Wednesday night through Thursday morning even if it did not make landfall.

More than 200 millimetres (eight inches) of rain has fallen in various places in the north the past day, and the volume could surge to one metre, the bureau warned.

Financial markets were closed, while offices and schools in the north, the area which is anticipated to be mostly affected by the storm, shut down.

All the flights and ferries between Taiwan and offshore islands were terminated, according to the transportation ministry.

As part of the government's preventive measures, the defence ministry deployed around 2,000 soldiers in some areas prone to be hit by flooding and landslides, and placed another 50,000 on stand-by.

President Ma Ying-jeou cut an overseas trip short by one day, flying back to Taiwan from a visit to the Caribbean via a stopover in the United States.