According to the Tehran University Seismological Center, the earthquake struck the city of Khoi in Iran's West Azerbaijan province (northwest) at 21:44 (local time; 20:14 Greece time).
"So far, three people have died and 816 have been injured as a result of this earthquake," said Mohammad Sadek Motamedian, governor of East Azerbaijan province, according to the official IRNA news agency.
Interior Minister Ahmad Vahidi visited Khoi to assess the situation and oversee the authorities' work, according to IRNA.
Iran, which sits on intersecting tectonic plates, has recently experienced several devastating earthquakes.
A magnitude 5.8 earthquake near Hoi An on January 18 injured several hundred people.
A 5.7-magnitude earthquake struck the village of Hambas-i-Olia (east) in February 2020, killing at least nine people across the border in Turkey.
The deadliest earthquake ever recorded in Iran, with a magnitude of 7.4, struck the northern part of the country in 1990, killing 40,000 people, injuring another 30,000, and displacing half a million.
With information from APE-MPE, AFP, and Reuters