BEIJING, Jan. 11 (Xinhua) -- China's meteorological authority renewed a yellow alert on Thursday for a cold front in central and eastern regions.

Alerts for a cold wave have lasted five consecutive days, according to the National Meteorological Center (NMC).

From Thursday evening to Friday, the temperature is expected to drop moderately in regions along and south of the Yellow and Huaihe rivers, the NMC said.

Meanwhile, low temperatures in parts of Shandong, Henan and Anhui will reach minus 10 to minus 12 degrees Celsius Friday morning.

Temperatures will begin to climb gradually from Friday to Saturday in most of the country and reach normal levels on Sunday.

On Thursday, the Ministry of Environmental Protection predicted more days of air pollution in north China during the first two months of 2018.

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