Skopje, as well as three other cities in North Macedonia, have been invaded by fog for several days, which has caused accidents and flight cancellations.

Authorities have put emergency measures in place to tackle rising smog levels.

Air pollution levels have increased 28 times the safety threshold set by the World Health Organization.

The government has recommended companies allow pregnant women and people over the age of 60 to miss work.

Residents burning materials to heat their homes, vehicle emissions, and industrial emissions are believed to be the main causes of smog.

According to the measurements of a Swiss company, Skopje is the third most polluted city in the world.