People walk past a statue on a foggy day in Cangzhou, North China's Hebei province, Dec 3, 2011. [Photo/CFP]

Heavy fog shrouded Shandong and Hebei provinces Saturday, crippling traffic, closing expressways and delaying flights.

Visibility was reduced to less than 200 meters in different parts of Shandong, and less than 50 meters in a few areas, according to the Shandong Provincial Meteorological Center.

Local authorities have been forced to shut five expressways, they said, and more than 40 flights at an airport in the provincial capital of Jinan have been delayed or canceled.

The neighboring Hebei province issued a red alert, the highest in the four-scale alert system, as the thick fog closed 15 express ways and left 14 flights delayed or canceled in the Shijiazhuang Zhengding International Airport.