Thick smog continued to affect India’s Delhi region on Sunday, November 12, despite a steady improvement in air quality levels over recent days. Experts warned another spike in pollution could be on the way after rains forecast for November 15.

Air pollution peaked on Thursday with hazardous levels of 486 registered on the air quality index (AQI), prompting schools to shut for the rest of the week. United Airlines also cancelled all flights to New Delhi.

Light rain expected in the middle of the week may bring down pollution levels but in the longer run the moisture in the air could trap pollutants and increase smog levels once again. Credit: Twitter/CP Aryal via Storyful