Hong Kong residents were advised to stay indoors on Monday, January 22, after pollution in the southern Chinese city reached “very high levels”.

Environmental Protection Bureau issued the warning, adding that children, the elderly and people with heart or respiratory illnesses were particularly at risk from the pollution, as the level of fine particulates (PM 2.5) in the air rose to an average concentration of 198 micrograms per cubic metre.

The AFP that reported high levels of pollution have heightened criticism of the city administration’s environmental record. On the Chinese mainland, a government crackdown on air pollution appeared to have cut into normal wintertime smog, with the air quality index rating for Beijing on Tuesday standing at just 25.

“The weather in Hong Kong today is hazy with sunny periods and light winds. Light wind hindered effective dispersion of air pollutants and led to accumulation of air pollutants in Hong Kong and the Pearl River Delta region since yesterday,” Hong Kong’s Environmental Protection Bureau said in a statement Monday.

This video shot on Tuesday shows conditions over Victoria Harbour, which had a PM 2.5 rating of 98. Credit: Iain Martin/Storyful via Storyful