Following a rainy day in various parts of Khuzestan Province on Saturday November 2, many people went to hospitals with serious bouts of choking and shortness of breath.

ISNA reports that 3,100 people reported serious respiratory symptoms in Khuzestan following the weekend rainfall.

The report adds that another 1,000 people sought hospital care on Monday.

An Ahwaz representative in Parliament told ISNA that at least 5,000 people have been treated in the southwestern province’s hospitals following what he referred to as “acid rain.”

A crisis committee is now reportedly investigating the causes of this event.

The World Health Organization has recognized Ahwaz, the capital of Khuzestan, as one of the world’s most polluted cities, citing heavy industry and low-quality car fuel as a major cause of this pollution.