A bus plunge in a Chinese province recently struck by icy weather killed at least 19 people as rescuers continued searching for bodies, state media reported.

On Tuesday afternoon the bus rolled 150 metres into the Chishui River in the southwest province of Guizhou, a hilly region where snow and icy rain recently blocked roads and toppled power lines.

The official Xinhua news agency reported that by late on Tuesday there were 19 confirmed deaths and 13 injured survivors.

The bus had 33 passengers when it left nearby Chishui city, but it was unclear whether anybody then left or joined the bus before the accident, Xinhua said.

The report did not say whether the bad weather played a part in the accident. Chinese roads and trains are now crowded with travellers heading back to work after the Lunar New Year holiday.

The recent brutal winter weather across much of China's southern half caused billions of dollars in damage and killed at least 80 people, but over the past few days the government has restored nearly all rail and road links.