The national railway system is going through a harsh test, with increasing pressure from passengers who lined up all night for a train ticket and the icy weather in the southern part of the country that could disrupt transport at any time.

A flood of people have waited in line before ticket windows at Beijing's several railway stations over the weekend, and tickets for all trains leaving Beijing were sold out in only 30 minutes after being put on sale on Saturday morning, the Beijing Times reported.

Tickets sold over the weekend are for ordinary trains leaving in the few days before the eve of the Spring Festival, which falls on Feb 3 this year.

A similar ticket-buying spree is expected to come again on Jan 27, when tickets for high-speed trains leaving in those few days ahead of the traditional family-reunion holiday are put on sale.

Meanwhile, the growth of railway passenger numbers has been speeding up day by day from Jan 22, with a remarkable rise of passenger volume compared with last year, the Ministry of Railways said on Sunday.

The latest data shows that nearly 5.28 million passengers took trains on Saturday, the fourth day of the travel peak season this year - up 23.5 percent compared with the corresponding day last year, the ministry said.

The railway ministry has vowed to sack any staff found scalping train tickets or helping scalpers.

"We'll immediately terminate the employment contract with any offenders," Vice-Minister of Railways Wang Zhiguo said at a news conference over the weekend in Beijing.

The ministry has invited more than 1,000 people to supervise the ticket sales nationwide, he said.

More than 1,800 scalpers have been arrested in recent joint efforts between the railway ministry and the Ministry of Public Security.

In addition to fears of being unable to secure a ticket, the public is also worried about the freezing weather that has been lingering in the southern part of China since the New Year began.

On Sunday, parts of Southwest China, southern Hunan province, western Guangxi Zhuang autonomous region, and Hainan province had snow or sleet. For some other areas in the country, snow has stopped, but the roads are still icy.

In the next three days, snowy weather will weaken in most regions, but the eastern areas in Southwest China will continue to see more rain and snow, according to a forecast by the national meteorological authority.

To avoid the travel disaster seen in early 2008 when unprecedented levels of heavy snow and freezing rain hit the southern part of the country, bringing traffic to a standstill at the peak holiday season, several ministries said they will work together this year to make sure people can arrive home on time.

Huang Ming, vice-minister of public security, said at the press conference on Saturday that expressways will not be blocked to traffic unless there is no alternative. In 2008, several expressways were closed by traffic police for fears of increasing traffic accidents on icy roads, but the shutdown made thousands of passengers stuck on road and increased pressure on railways.

Wang Zhiguo also vowed that the ministry will allocate more manpower for railway safety inspection and deploy devices to remove ice and snow to prevent railways being paralyzed by icy rains or snow.

Railway stations will also prepare enough food and water for stranded passengers, he said.

"We'll try to make people's journey safe to ensure them a good Spring Festival holiday," Wang said.