Heavy smog blankets Harbin; cities to coordinate efforts

Ever since coal-burning heating systems were fired up in mid-October, residents in Harbin, Heilongjiang province, have suffered from virtually constant smog, arousing queries about what the government is doing about it.

On Tuesday morning, the city's meteorological authorities upgraded the yellow alert for smog to orange, the second-highest level in the nation's four-tier emergency response system.

The air quality index in the city hit 500 from Monday evening to early Tuesday, according to the National Environmental Monitoring Center. Anything above 300 is considered hazardous.