Thick fog blanketed areas of north, central and east China on Wednesday, delaying flights, reducing road visibility and forcing sections of expressways to close temporarily.

Heavy fog shrouded the central province of Hubei and forced six expressways to close.

In Wuhan, Ezhou and Xiaogan cities, road visibility was reduced to less than 50 meters. Meteorological observatories in the three cities raised the warning level to red, the highest.

In north China's Tianjin Municipality, one expressway was closed and the road visibility was reduced to 100 m.

In Hefei City in east China's Anhui Province, most flights out of the city were delayed by the thick fog.

In Nanjing City of east China's Jiangsu Province, traffic jams clogged downtown streets for about two hours in the morning.

According to observatory experts, the fog was caused by a combination of high humidity and lower temperatures. They predicted that the fog would affect the cities again on Thursday morning.

(Xinhua News Agency December 19, 2007)