Beijing urged residents to stay indoors on Wednesday as emergency measures were rolled out aimed at countering a heavy cloud of smog blanketing the Chinese capital and swathes of the country.
The municipal government said children, the elderly and people sensitive to poor air quality should remain indoors, after authorities announced the closure of 103 factories and ordered 30 per cent of official cars off the road on Tuesday.
By 11am on Wednesday, Beijing's Capital International Airport had cancelled or delayed about a dozen domestic flights between Beijing and major northern Chinese cities.
Up to 15 international flights were cancelled to destinations such as Tokyo, Istanbul, Moscow, Kuala Lumpur and Helsinki.
As the thick cloud of toxic air choked Beijing for the third consecutive day, the now familiar sight of mask-wearing pedestrians venturing out on heavily-polluted roads was broadcast regularly on state media.
Beijing shrouded in smog. Video: Simon Song
Visibility in central Beijing was reduced to 300 metres, according to China Central Television, causing 29 flights to be cancelled and another seven delayed.
The state-run broadcaster also showed images of the eastern province of Jiangsu – some 1,000 kilometres south of Beijing – covered in a thick blanket of smog.
The US embassy’s air quality index reading for Beijing stood at 336 and “hazardous” at 1pm on Wednesday. The index rates a reading over 150 as “unhealthy” and above 300 as “hazardous”.
Meanwhile, the Beijing Municipal Environmental Monitoring Centre gave the figure as 292 at midday, indicating the capital’s air was “heavily polluted”.
The toxic air is the fourth serious bout in recent weeks, and the winter of smog has sparked an Internet outcry and anger from state media.
China’s pollution problems are blamed on the country’s rapid urbanisation and dramatic economic development.
On Tuesday, residents across huge swathes of northern China battled through choking pollution at extreme levels, as Beijing was plunged into toxic twilight for the fourth time this winter.
Visibility was reduced to around 200 metres in parts of the capital, where mask-wearing pedestrians groped through a murky haze, despite warnings from authorities to stay indoors unless absolutely necessary.
In a Beijing city office visited by AFP, up to 20 workers who worried that the pollutants could penetrate indoors took extra precautions, wearing gas-mask style protective headgear at their desks.
State broadcaster China Central Television gave the smog’s second day huge airplay, showing vehicles using full headlights in mid-morning to light their way through the noxious cloud.
More than 100 flights were delayed or cancelled at Zhengzhou Airport in Henan on Tuesday, television reports said, adding that the haze would last until Thursday. At Beijing airport, 61 departing flights were delayed in the morning.
In the eastern province of Shandong, almost 2,000 passengers were stranded at Qingdao’s main airport after it shut with 20 flights cancelled as visibility dropped to 100 metres, according to the official Xinhua news agency.
The smog of recent days has hit a total area of 1.3 million square kilometres (520,000 square miles), the Ministry of Environmental Protection said – about twice the size of France.
It described the cities of Beijing, Tianjin, Shijiazhuang and Jinan as “gravely polluted”.
The National Meteorological Centre (NMC) announced late Tuesday that it was introducing a three-tier colour-coded weather warning system to alert the public about the severity of smog, according to Xinhua.
Yellow will indicate moderately smoggy weather, with orange for severe conditions and red for extremely severe levels of smog, the report said.
Beijing’s winter of smog has sparked an Internet outcry and anger from state media.
The China Daily reiterated its calls for firm action on Tuesday, directing them at the capital’s newly-installed mayor Wang Anshun, who formally took over on Monday.
“What do Beijing residents expect of their new mayor?” asked the newspaper in an editorial. “Of all the things that need improving, cleaner air will be at the top of many people’s wish list.”
Wang was quoted by Xinhua as saying: “The current environmental problems are worrisome.”
The Beijing News went as far as to suggest banning or regulating next month’s traditional and hugely popular New Year fireworks in the capital. Pollution readings spiked last year after the city’s skyline lit up with explosions.