Iranian authorities have shut down schools and canceled sporting events around Tehran due to thick smog covering the capital city.
Authorities decided to close kindergartens and primary schools in all but two cities in the Tehran Province, which is home to around 14 million people, the semiofficial Tasnim news agency reported on December 17.
Schools were also ordered to remain closed the following day, and sports competitions scheduled for December 18 were canceled as well.
Emergency officials in Tehran deployed ambulances and buses to eight main squares in the Iranian capital, saying that all of the city's hospitals were ready to accept patients with respiratory difficulties.
Authorities also placed restrictions on road traffic.
Tehran is one of the most polluted capital cities in the world, and every winter, cold air and a lack of wind trap smog over the city.
Iran's Health Ministry estimated that pollution in 2012 contributed to 4,500 premature deaths in Tehran and to about 80,000 nationwide.