China renews yellow alert for thick fog

China's national observatory on Thursday renewed the yellow alert for thick fog in some parts of the country.

Throughout Thursday, heavy fog is expected to blanket central and southern parts of the Yellow Sea, the western part of the East China Sea, and coastal waters of Jiangsu, Zhejiang and Fujian, according to the National Meteorological Center.

Drivers have been asked to observe safe speeds, and airports, freeways and ports have been told to take appropriate safety measures.

China has a four-tier color-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.