BEIJING - Mask-wearing Beijing residents endured a third day of pollution at hazardous levels on Sunday, as authorities warned that a thick cloud of smog may not lift from the Chinese capital until midweek. As the dense smog shrouded large swathes of northern China, flights were cancelled and traffic delayed as visibility was reduced to 100 metres in some areas. The dangerously poor air quality was highlighted by a steady stream of news broadcasts on state television, many of which warned residents against venturing outside. The pollution also provoked China’s huge number of microbloggers to take to the internet.

Rapid economic growth has led to a dramatic increase in the consumption of coal and car-clogged city streets.

“The foreign media is laughing at us. I agree with their laughter,” said Hu Xijin, the editor of the state-run Global Times newspaper on Weibo, China’s version of Twitter.

“This is a warning to the Government and Beijing’s citizens. We have to think about what kind of modernisation we want and how to manage it.”

Hu said the pollution issue would be on the front page of his newspaper on Monday.

Beijing’s municipal environment warning centre issued its second alert in two days, warning people to avoid outdoor physical activity.

The centre also urged government officials to set an example to other residents, by not using their cars.

Doctors at the Beijing Chaoyang Hospital and the Beijing Children’s Hospital said that the number of patients with respiratory disease had jumped sharply in the past few days, according to Xinhua news agency.

It also reported that the municipal authorities have ordered outdoor sports to be stopped at primary and middle schools in the most polluted areas until Tuesday.