The government said residents of the cities of Skopje and Tetovo had been granted free travel on trains and buses in the last few days of December to discourage use of cars while those with chronic illnesses and pregnant women were excused from work. Outdoors sports activities were also banned.
Local media said shops ran out of face masks as many people sought to protect themselves from the subzero and largely windless air in Skopje, which sits at the bottom of a valley.
A World Health Organisation (WHO) study published early this year said Skopje was among 10 European cities with the highest concentration of toxic particles.
Skopje and four other Balkan cities in that list rely for their energy including heating during frigid winters on high-polluting lignite coal, a holdover from decades of old Communist Yugoslav rule._______________________