Services at Chinese airports are returning to normal after fog forced some flights to be delayed or canceled, China's air regulator said Wednesday.

More than 360 flights had been delayed in Shanghai, Beijing, Guangzhou and Haikou as of 11 a.m., the Civil Aviation Administration of China said in a statement on its website.

A spokesman for China Southern Airlines said the company will keep a close eye on the weather, help delayed passengers reschedule their tickets and arrange accommodations for them in order to minimize the fog's impact on their travel.

Although airport services are returning to normal, the spokesman suggested passengers check with their airlines before travelling as the fog is expected to continue to shroud parts of China on Thursday.

Heavy fog will reduce visibility to less than 200 meters in some parts of central and eastern China, the National Meteorological Center said Wednesday.