Beijing, Dec 12 : China's meteorological authority on Saturday has renewed its yellow and blue alerts for fog and a cold wave across the country. In an update, the National Meteorological Center said the yellow alert was issued for fog that will cover parts of Hebei, Tianjin, Shandong, Anhui, Jiangsu, Zhejiang, Hubei and Hunan provinces, reducing visibility to less than 200 metres, reports Xinhua news agency. Due to low visibility, drivers have been advised to maintain safe distance and control speed, while airports, expressways, piers should take precautionary measures to ensure transport safety, the centre said. Meanwhile, the blue alert was renewed for cold waves in 17 provincial-level regions, advising residents to take shelter from the wind and keep warm. Parts of Inner Mongolia, Shaanxi, Hunan, Guizhou and Guangxi will see temperatures fall by up to 10 degrees Celsius over the next three days. /IANS