Tourists wearing masks visit Beijing’s Tiananmen Square, which is shrouded in heavy smog in Beijing on Sunday. According to the Beijing Municipal Environmental Monitoring Center, the air pollution was expected to peak in parts of Beijing on Monday. Photo: IC

Mask-wearing tourists visit Tiananmen Square on Sunday. Choking smog rolled into Beijing and Shijiazhuang, capital of neighboring Hebei province, at 1 p.m. that day, when the average level of the Air Quality Index (AQI) was over 200. The AQI in Beijing had risen above 218 by 9 p.m. Photo: IC

A foreign tourist wears a face mask while visiting Tiananmen Square on Sunday. Photo: IC

A woman wearing a face mask (right), accompanied by a young girl, visit Tiananmen Square on Sunday. The smog was forecast to last two days, and air quality should be good again by Tuesday. Photo: IC