A thick fog continued to shroud central and eastern parts of China Thursday, leading to flight delays and expressway closures.

It was the second day that China's transport network was affected by the heavy fog, which reduced visibility to less than 10 meters in extreme cases.

In Shanghai, about 80 flights were delayed at the city's two airports, stranding 3,000 passengers.

At the Hangzhou Xiaoshan International Airport in neighboring Zhejiang Province, another 3,000 passengers were stranded as dozens of inbound and outbound flights were delayed.

Major expressways were forced to shut down in different provinces, such as Henan, Zhejiang and Anhui.

Local meteorological authorities have issued heavy fog warnings, advising citizens to reduce outdoor activities and drivers to take precautionary measures.