An old man died of a heart attack and most of the injured were hurt while trying to run out of buildings and were released from hospitals after treatment, IRNA reported.
Schools in Alborz Province and two cities of Tehran Province closed on Wednesday.
The quake is an aftershock of a 5.2-magnitude quake that struck Mallard, a town near the capital, on Dec. 20, killing two people and injuring 117.
It was also felt in Tehran where many residents spent the night outside, in cars, or in sports facilities and other buildings turned into rescue centers.
Crisscrossed by several major geological fault lines, Iran is one of the world’s most quake-prone countries. In 2003, a magnitude 6.6 quake in Kerman Province killed 31,000 people and flattened the ancient city of Bam.