Airports, schools remain closed as thick smog blankets Chinese city of Harbin

Schools, major roads and an airport remained closed Tuesday, as a thick cloud of filthy smog smothered the northeastern city of Harbin.

Meteorologists in the city, which is famous for its annual ice festival, issued a red alert for fog at 5 a.m. Tuesday, with visibility in some central areas of the city down to less than 20 meters (65 feet), the state-run Xinhua news agency reported.

Video from China's state-run CCTV showed some people -- obscured by smog even just steps away -- wearing masks over their mouths as they walked in the province. Some drivers who braved the roads flashed hazard lights.

Kindergartens, primary and junior middle schools were ordered to suspend classes for a second day, while Harbin Taiping International Airport remained closed -- with 250 flights canceled on Monday alone, according to Chinese state media.