It has also brought China unwanted negative publicity six months before the Summer Olympics in Beijing.

President Hu Jintao chaired an emergency Politburo meeting on Sunday for the second time in a week to discuss rescue efforts.

"We have to be clear-minded that the inclement weather and severe disaster will continue to plague certain regions in the south," said a statement issued after Sunday's meeting. "Relief work will continue to face challenges, posing a tough task."

The China Meteorological Administration said the weather was the coldest in 100 years in central Hubei and Hunan provinces, going by the total number of consecutive days of average temperature less than 1 degree Celsius (33.8 degrees Fahrenheit).

But it expected brighter weather ahead, though fog could become a problem and temperatures at night would likely still be below freezing, slowing the thaw.

"It is still necessary to remain alert for possible low temperatures, frozen rain, snow, freezing and heavy fog," said administration head Zheng Guoguang.

He added the cold snap had caught the country off guard, in an area unprepared for such heavy snow. But climate change could see more extremes in weather in China, Zheng warned.

Four people died after a snow-laden roof collapsed at a fuel station in the eastern city of Nanjing on Sunday, Xinhua news agency said. One person was killed in a stampede at Guangzhou railway station in the south as people rushed to board trains.

Roads and railways, some of which have been blocked for days, have started to move again, and fewer flights were being cancelled, state media said, offering a glimmer of hope.

The United States and Singapore pledged emergency aid of US$150,000 and $500,000 respectively, Xinhua said, as several other countries sent condolence messages.

CAJOLED TO SKIP HOLIDAY

Authorities in the southern city of Guangzhou said their priority was to clear the backlog of travellers, having cajoled millions of migrant workers to stay put and skip the holiday.

Elsewhere, efforts turned to restoring power and water, which some cities, such as Chenzhou in the south, have been without for more than a week, causing some to question China's ability to handle emergencies months before Beijing holds the Olympics.

"Without power the only information we have been getting is by SMS from the government," said Chenzhou resident Zheng Ninghong, tending a fruit stall amid the slush.

"There was one, I think, that said it would get warmer, but what we need is electricity."

China has largely avoided unrest throughout the crisis, in part due to the 519,000 soldiers and more than 1.6 million paramilitary police that have been deployed throughout the country to help with disaster relief and crowd control.

The government continued to lionize those working to restore normalcy, giving three policemen who died during the storms the title of "hero and model of all Chinese policemen".

Pictures from Wuhan, capital of the central province of Hubei and lying at the middle reaches of the Yangtze and Han rivers, showed cars blanketed not by snow, but by ice. Riverside barriers and trees were draped in huge icicles.

The China Daily quoted an economic planning official as saying power plants in Beijing and Shanghai had only enough coal for less than seven days.