The decision to shut schools and universities in the capital was announced Friday by Deputy Governor Mohammad Taqizadeh, after a meeting of an emergency committee for air pollution which was widespread across Iran cities.

“Due to increased air pollution, kindergartens, preschools and schools, universities, and higher education institutes of Tehran Province will be closed,” he said.

Speaking on Saturday, Taqizadeh said all schools will be shut in Tehran Province on Sunday except for three counties.

Two soccer matches in Persian Gulf Pro League were canceled on Saturday over dangerously high levels of air pollution in Tehran Province.

Persepolis match against Nassaji Mazandaran as well as Paykan match against Tractor, which were scheduled for Saturday, were postponed.

An odd-even traffic scheme was imposed to restrict the number of private vehicles on roads of the capital city and trucks were banned outright in Tehran Province.

The young and elderly and people with respiratory illnesses were warned to stay indoors and sporting activities were suspended on Saturday, the start of the working week in the Islamic Republic.

Schools were also closed on Saturday in the northern province of Alborz and in the central province of Isfahan.

Other areas where schools were shut included the northeastern city of Mashhad, Orumiyeh city in northwestern Iran and Qom, south of Tehran.

In Tehran, average concentrations of hazardous airborne particles reached 146 micrograms per cubic meter on Saturday, according to air.tehran.ir, a government-linked website.

The pall of pollution has shrouded the sprawling city of eight million for days and is only expected to dissipate on Monday when rain is forecast.

Air pollution was the cause of nearly 30,000 deaths per year in Iranian cities, state media reported earlier this year, citing a Health Ministry official.

The problem worsens in Tehran during winter, when a lack of wind and the cold air traps hazardous smog over the city for days on end – a phenomenon known as thermal inversion.

The city’s pollution is mainly caused by heavy-duty vehicles, motorbikes, refineries, and power plants, according to a World Bank report released last year.