PICTURES, VIDEO

Dangerous pollution levels blight China's Harbin, schools, airport closed

A man pushes a bike onto a bridge during a day of heavy pollution in Harbin in north-east China's Heilongjiang province on Monday, Oct 21, 2013. -- PHOTO: AP
A man pushes a bike onto a bridge during a day of heavy pollution in Harbin in north-east China's Heilongjiang province on Monday, Oct 21, 2013. -- PHOTO: AP
A workman carries a road barrier on a street under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
A workman carries a road barrier on a street under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
A statue is seen under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP 
A statue is seen under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP 
Residents with masks on their faces are seen under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
Residents with masks on their faces are seen under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
Local residents dance on a square under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
Local residents dance on a square under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
Local residents dance on a square under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
Local residents dance on a square under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
A man stands next to an airplane under heavy smog in Harbin, north-east China's Heilongjiang province, on October 21, 2013. -- PHOTO: AFP
A man stands next to an airplane under heavy smog in Harbin, north-east China's Heilongjiang province, on October 21, 2013. -- PHOTO: AFP
A woman stands on a bridge under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
A woman stands on a bridge under heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
A woman wearing a mask walks in the smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
A woman wearing a mask walks in the smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. -- PHOTO: AFP
A policeman gestures as he works on a street in heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. Thick smog enveloped a Chinese city for a third day on Tuesday, with schools and a regional airport shuttered and low vis
A policeman gestures as he works on a street in heavy smog in Harbin, north-east China's Heilongjiang province, on Oct 21, 2013. Thick smog enveloped a Chinese city for a third day on Tuesday, with schools and a regional airport shuttered and low visibility forcing ground transport to a halt in places. -- PHOTO: AFP

BEIJING (AFP) - Thick smog enveloped a Chinese city for a third day on Tuesday, with schools and a regional airport shuttered and low visibility forcing ground transport to a halt in places.

Air pollution levels in Harbin, a north-eastern city of more than 10 million people and the host of a popular annual ice festival, remained far above the levels deemed safe by the World Health Organization.

Images showed the city's roads shrouded in smog, with visibility in some areas reduced to less than 50 metres.

Flights remained severely delayed, after more than 250 flights were cancelled at the local airport on Monday, according to Chinese media.

Monitoring stations on Tuesday morning showed that concentrations of PM2.5, the tiny airborne particles considered most harmful to health, reached 822 micrograms per cubic metre in the city.

That figure was down from Monday's level of 1,000 micrograms per cubic metre but still more than 30 times the WHO's recommended standard.

The overall air quality index remained above 500, the highest level on the Chinese scale.

The smog in Harbin came as it activated its public heating system ahead of the frigid winter, state media said.

It is China's latest major pollution-related episode.

The issue causes significant public anger and several Chinese newspapers carried images from Harbin on their front pages Tuesday.

In January, thick smog blanketed Beijing - with similar PM2.5 levels to Harbin this week - garnering headlines, as well as a nickname "airpocalypse", in news reports around the globe.

At the time, Harbin escaped the worst of the pollution, but huge areas of northern China have been shrouded by smog at various times this year.

Pollution from rapid development and heavy coal use plagues wide swathes of China, prompting public criticism and pledges from the country's leadership to make improvements.