A woman with a dog crosses a road in the fog on Friday in Anhui province, southern China. The National Meteorological Center issued this year’s first red alert for fog on Friday morning as visibility in some parts of China dropped to less than 200 meters. Photo: VCG

A lone person waits to cross the street amid heavy fog in Shanghai on Thursday. Photo: IC Photo

Residential buildings are covered in heavy fog and haze in Shanghai on Friday morning. Photo: VCG

Haze envelopes buildings in Huaian, Jiangsu province, a city on the Huai River, on Tuesday. Photo: IC Photo

An aerial view of the fog-covered Suzhou City Moat in Jiangsu province on Friday. Photo: VCG

People walk on the fog-covered bank of the Qinhuai River in Nanjing, Jiangsu province, on Friday. Photo: VCG

A policeman directs traffic and reminds drivers to maintain a safe distance while driving on Thursday evening in Zaozhuang, Shandong province. Photo: VCG

Some sections of expressways are closed due to the poor weather conditions, including the Changshen expressway in Lian Yungang, Jiangsu province. Photo: VCG