Frustration mounts as toxic smog shrouds the Balkans Winter brings its annual toxic smog to the Balkans, where the pollution is fuelled in large part by the coal and wood fires that many poorer residents rely on for heating. In recent weeks, Balkan capitals including Belgrade, Sarajevo, Skopje and Pristina have been ranked among the world's top 10 most polluted major cities, according to the monitoring application AirVisual. There have been a spate of protests in cities around the region as citizens demand clean air and from governments that have been slow to react to the crisis. \\n IMAGES AND SOUNDBITES