India's financial capital Mumbai has witnessed a drop in air quality this month, authorities said.

Withdrawing rains and construction work have caused the air quality to deteriorate, officials said.

Delhi usually makes headlines for dangerous levels of air pollution during the winter months.

But Mumbai, which has a vast coastline and is considered to have better air quality, overtook Delhi several times this month.

The level of PM 2.5 - fine particulate matter that can clog lungs and cause a host of diseases - was 166 in the city on Thursday compared to 117 in Delhi, according to government data.

Levels between 101 to 200 are considered moderate while those between 201 and 300 are categorised poor.

Parts of Mumbai have seen pollution levels oscillate between moderate and poor this week.

"This is not chemical but dust pollution," Minister Deepak Kesarkar told the PTI news agency on Thursday. "The ongoing work of development projects like road and metro is causing pollution in the city."

Sunil Kamble, chief of India's weather office, said the withdrawal of monsoon rains from the city on 10 October also played a part in worsening pollution levels.

Kesarkar, who works with the city government, said it was looking for solutions including anti-smog guns to bring down pollution levels in the city.

Bad air quality in Indian cities is causing serious health issues to people. A Lancet study reported that pollution led to more than 2.3 million premature deaths in India in 2019.