Packing maximum sustained wind speeds of 137 kilometres (85 miles) an hour, Danas is expected to sweep northwards along Taiwan's west coast overnight, the Central Weather Administration said in an advisory.

At least 28 people have been treated for minor injuries, according to the National Fire Agency.

Danas dumped more than 500 millimetres (20 inches) of rain across southern Taiwan over the weekend, the weather agency said, warning of heavy to torrential rain across the rest of the island as the typhoon moves north.

"Tonight through tomorrow morning will see the strongest wind and rain impacts," the weather agency said.

Most of the 2,853 people evacuated from their homes were in mountainous areas around the southern port city of Kaohsiung, the National Fire Agency said.

At least 10 landslides were recorded and 49 areas flooded, but the water has since receded, it added.

Taiwan is accustomed to frequent tropical storms from July to October.