SKOPJE, Macedonia (AP) — Macedonian authorities have made public transport temporarily free for all in the capital Skopje, as part of a batch of emergency measures to fight high air pollution levels.

The government said Monday that pollution in Skopje was recorded at more than four times above safety levels and that it has decided to ban heavy vehicles entering the city center. It has also excused pregnant women and people over 60 years of age from work.

Skopje has severe air pollution problems every winter, as a result of industrial emissions, smoke from wood-burning stoves and exhaust fumes from old cars.

The measures will remain in effect until pollution levels drop.