Heavy fog on Saturday forced flights and expressways to close in east and central China, delaying the return of thousands of people at the end of the weeklong Spring Festival break.

Millions are on the move, heading back to their places of work on the last day of a Lunar New Year holiday, but the National Meteorological Center (NMC) said fog and haze would continue to blanket parts of Shandong, Jiangsu, Anhui, Hubei, Jiangxi, Hunan, Guizhou, and Chongqing.

The fog would reduce the visibility to less than 1,000 meters in some regions, and even to less than 200 meters in some areas, it added.

The Shandong provincial observatory issued a heavy fog warning (with visibility below 500 meters) at 8:40 a.m. and forecast the conditions would continue for 12 hours, mainly in central and southern Shandong.

The inter-provincial expressways within Shandong were closed. All 118 outbound flights from Qingdao International Airport and 98 outbound flights from Jinan International Airport were delayed.

The heavy fog also shrouded six cities in central Hubei Province, with visibility down to 100 meters, said Huang Zhiyong, the chief weatherman of the observatory of Wuhan, the provincial capital.

He said rain, high humidity and temperature drops at night caused the fog, which was forecast to last to Sunday.

The estimated number of travelers on the first post-festival travel peak is not available, but it is expected to surpass Thursday's 4.24 million rail passengers, the latest official figure, and 47.6 million road travelers and 1.23 million waterway tourists on Friday.

China Central Television (CCTV) said at noon that an estimated 4.9 million passengers were expected to travel by train and 56 million people would embark on road trips Saturday.

The number of air passengers was still being compiled by the civil aviation administration. An estimated 660,000 people traveled by air on the last day of Spring Festival holiday in 2008.

The NMC said light or moderate snow would hit parts of Xinjiang, Tibet, Gansu, Ningxia, Shaanxi, Shanxi on Saturday evening, while moderate rain was expected in Henan, Hubei, Sichuan, Chongqing, Guizhou and Guangdong.

The NMC urged transport departments to take precautions to ensure an orderly peak travel period.

The authorities are seeking to avoid traffic disruption that would lead to thousands of stranded passengers, which happened during last year's Spring Festival rush as a result of rare snow and ice in south China.

In order to meet rising travel demand, the Ministry of Railways said Friday it would arrange more trains in provinces such as Sichuan, Hunan, Hubei and Jiangxi, where migrant workers are expected to swarm on to trains heading to coastal regions in the hope of finding jobs.

(Xinhua News Agency January 31, 2009)