China’s prime minister rushed south from the capital to show his concern for millions of travellers stranded by snowstorms and blizzards, only to fall victim himself to the worst winter weather in China for half a century.

The extreme weather is now thought to have killed more than 50 people after two buses crashed today.

In the worst accident since the blizzards began, a bus slid off an icy mountain road in Guizhou province killing 25 people according to the State Administration of Work Safety. Another four people died when a bus in north western Gansu province flipped over.

Snow has closed 19 airports in central and southern China. Heavy ice has downed power lines along many major railway lines. Sleet and slush have blocked roads halting thousands of trucks loaded with coal, food and passengers.

The bitter winter weather has hit at the peak of the biggest human migration on earth, when hundreds of millions of people head home to spend the Chinese lunar new year holiday, which falls next Thursday, with their families.

Premier Wen Jiabao’s journey underlined the extent of the crisis. He flew out of Beijing today en route for the south-central province of Hunan. But he had to land at an airport in the neighbouring province of Hubei and had to complete his journey to Changsha by train.

Speaking through a megaphone to huge crowds hoping to catch a train out of the station, Mr Wen said: "First of all we need to get the electricity running, then it won't take much time for everyone to be able to go home and pass the Lunar New Year." One woman wept as he spoke. Others applauded.

The most important task now was to clear ice from the power lines so that the trains could resume running.

But untold millions may fail to get home for the holiday that is a traditional time for family reunions amid warnings the cold snap that has dumped unusual snow across the south and centre of the country could continue for another week.

Authorities in southern Guangdong province are urging the millions of migrant workers who fill its manufacturing industries to stay put until after the main festival. More than half a million passengers are stranded in Guangzhou, the provincial capital, because of snow blocking the main south-north railway line to Beijing.

Times Recommends

• UN may halt 400-year-old 'freedom of the seas'
• Where the Rosetta belongs can’t be set in stone
• Gas deal on hold, but Ukraine may pay in the end