Due to increased air pollution in Sarajevo on Tuesday, city authorities have declared a "warning phase," urging locals to avoid staying outside and to reduce their outdoor activities.

People with chronic respiratory and cardiovascular issues, children, pregnant women, and elderly, are advised to spend time in fresh air as much as possible. Presumably this refers to the air outside of the city itself.

According to the air quality ratings reported by the IQAir website, Sarajevo was among top 10 most polluted cities in the world on Tuesday again, and the most polluted one in Europe, with the air quality there categorized as “unhealthy’.

The concentration of PM2.5 particles was 26.4 times above the air quality guideline set by the World Health Organization. Locals are advised to wear masks whenever venturing outdoors, and to avoid outdoor exercise, and also to use air purifiers at home and to keep windows closed, in order to avoid the polluted outdoor air.