Toxic smog engulfed much of northern India on Monday and pollution readings in New Delhi hit their highest of this pre-winter season, after dense fog overnight.

India's capital city of Delhi has virtually shut down as air pollution hit "severe plus" levels, according to Indian government officials in its pollution control authority.

Dense smog continues to engulf most parts of northern India on Monday with readings of air quality in the capital New Delhi reaching their highest levels this year after dense

Delhi overtook Pakistan ’s Lahore as the world’s most polluted city in Swiss group IQAir’s live rankings, with an air quality index (AQI) score of more than 1,000, which is considered “hazardous”, but India ’s pollution authority said the AQI was around 350.

Hundreds of millions of Indians breathe some of the world’s most toxic air all year round. Air pollution in the capital area that’s home to about 30 million people is especially stubborn. In winter, the cold weather actually makes the smog even worse — and potent.

Unhealthy