The quake is the deadliest in the world this year.
Most people who died were in western Iran in Sarpol-e-Zahab, a town 15km (10 miles) from the border, and other parts of Kermanshah province.
The town's main hospital was severely damaged, leaving it struggling to treat hundreds of wounded people, state TV reported.
A woman and her baby were pulled alive from rubble in the town, Iranian media said.
Many buildings in the town appear to have collapsed, amateur video posted to Twitter by a radio station showed.
Running water and electricity cut out in some cities, and after buildings collapsed people were forced to spend hours outdoors in parks or streets in cold weather.
Many homes in the predominantly Kurdish mountainous area are made of mud bricks and are vulnerable in quakes as large as Sunday's.