Heavy smog has prompted Chinese authorities to cancel hundreds of flights and shut motorways in northern China.
Flight cancellations and highway shutdowns disrupted travel on the first day of the New Year holidays on Sunday.
The recent uptick in air pollution started on Friday and is expected to continue for a week.
Large parts of the north have been dealing with heavy smog since mid-December last year, forcing authorities to take measures to cut hazardous gas emissions. The measures have included ordering hundreds of factories to close and restricting car movement on motorways.
Meanwhile, in the capital, Beijing, 24 flights were canceled at the city’s main airport and all buses traveling from the airport to neighboring cities were suspended, the airport said in a statement on social media.
In Tianjin, a two-hour drive from Beijing, the smog was not as hazardous as the capital health-wise, but visibility was much worse, with more than 200 flights canceled at Tianjin airport, authorities in the city said. They also imposed road traffic restrictions in Tianjin.
In Shijiazhuang, the provincial capital of Hebei Province, which surrounds most of Beijing, about two dozen flights were canceled and eight flights diverted to other airports because of the smog, local media reported.
In total, 24 Chinese cities have issued red alerts for high air pollution and 21 have issued orange alerts, including Beijing and Tianjin.
Air pollution alerts are common in northern China, especially during the cold winter season, when demand for energy rises in a country reliant on burning coal. The country’s northern parts burn hundreds of millions of tonnes of coal each year for generating power and heating.
China, which is regarded as the industrial zone of the world, began its “war on pollution” in 2014. Since then, Chinese authorities have been taking measures to reduce emission of hazardous gases such as CO and Co2.
Despite their efforts, China, alongside the US, is one of the main countries causing gas emissions that aggravate global warming.