Sarajevo was one of the world's most polluted cities on Saturday

With an air quality index (AQI) of 335, Sarajevo is only second to the Indian city of Delhi, which has an AQI of 389. They are followed by Lahore (Pakistan), Kathmandu (Nepal), Kabul (Afghanistan) and Belgrade.

Kobe (Japan) is at the bottom of the list, with an AQI of 5.

Authorities in Canton Sarajevo have declared a state of alert because of the pollution.