TEHRAN - Two football matches in Iran Professional League were postponed after the Iranian capital was cloaked in dangerously high levels of air pollution.

Persepolis match against Nassaji at the Azadi Stadium as well as Paykan and Tractor match in Shahre-Qods Stadium, located west of Tehran, have been postponed.

Severe air pollution had already led authorities to close schools in Iran’s capital.

Air pollution was the cause of nearly 30,000 deaths per year in Iranian cities.

Each winter, Iran's sprawling capital suffers some of the worst pollution in the world through thermal inversion -- a phenomenon that traps hazardous air over the city.