AP — Iran’s state-run IRNA news agency reports that authorities in the capital Tehran have decided to close down all kindergartens, schools and universities because of high levels of air pollution.

The Friday report quotes Tehran Province Deputy Gov. Mohammad Taghiizade as saying a special committee made the decision following days of high air pollution levels that are expected to get higher on Saturday, the first working day of the week in Iran.

All sports activities were canceled and authorities asked citizens, especially the elderly and children, to avoid unnecessary traffic in the city.

Tehran has suffered from dangerous levels of pollution and smog since mid-November. In the mornings, the sun has been barely visible owing to the city’s smog.

Tehran’s air is among the most polluted in the world.