Authorities evacuated more than a million people as south-east China braced for the onslaught from powerful Typhoon Krosa, which killed at least two in Taiwan.

Packing winds of 180 kilometres an hour, at 8pm (10pm AEST) Krosa was 455 kilometres off the coastal city of Wenling in Zhejiang province, Xinhua news agency said, quoting the provincial observatory.

By Saturday evening (local time), Zhejiang and neighbouring Fujian had evacuated more than one million people as the typhoon was expected to make landfall in the region Sunday.

Zhejiang evacuated more than 837,000 residents and recalled more than 32,000 boats to port, Xinhua said, while Fujian had relocated about 230,000 people and recalled nearly 37,000 vessels.

More than 500,000 holiday-makers who had flocked to the coast for the week-long National Day holiday were evacuated, Xinhua said, quoting the provincial tourism bureau director Zhao Jinyong.

Meanwhile rescuers say Krosa left two people dead, two missing and at least 17 others injured earlier as it pounded Taiwan with powerful winds and torrential rain.

In Taipei, a 30-year-old man was killed when mudslides crushed his house and rescuers were digging desperately through the ruins for his missing 60-year-old father, said the National Fire Agency, which coordinates rescue work.

A 79-year-old man fell to his death from a roof while a cook went missing when the hostel he worked for in the north of the island was hit by mudslides, it said.

Floods in central Vietnam unleashed by another typhoon, Lekima, have killed at least 17 people, as rescuers struggled to reach communities submerged by the heavy rains.

- AFP