Pakistan’s industrial hub, Karachi on Thursday ranked second among the most polluted cities in the world.

According to the Air Quality Index, the port city today is the second most polluted city in the world. The amount of polluted particles in the city's air has been recorded at 260 particulate meters.

Meanwhile, Lahore ranked fifth in the list of polluted cities in the world with 218 particulate meters.

India's capital New Delhi topped the list followed by Karachi and Bangladesh's capital Dhaka. According to the classification, pollution from 151 to 200 degrees is harmful to health.

Pollution from 201 to 300 degrees is extremely harmful to health, while more than 301 degrees indicates dangerous pollution.