More than 1,000 rescuers worked through the night to free people trapped under rubble and reach some of the more remote villages affected, the Associated Press reported. Television also showed people being evacuated on stretchers, while others underwent treatment for broken limbs and concussions on hospital beds.
By early afternoon on Sunday, state television was reporting that search operations had ceased. Hundreds of tents had been set up to house the homeless, it added.
Thousands huddled in makeshift camps or slept in the street after Saturday's quakes in fear of more aftershocks, 60 of which had already struck. A lack of tents and other supplies left them exposed to the night chill, one witness told Reuters.
"I saw some people whose entire home was destroyed and all their livestock killed," Tahir Sadati, a local photographer, said by telephone. "People need help, they need warm clothes, more tents, blankets and bread."
The worst damage and most casualties appeared to have been in rural villages around the towns of Ahar, Varzaghan and Harees, near the major city of Tabriz, Iranian media reported.
Many villages are hard to reach by road, hindering rescue efforts. Hospitals in Tabriz, Ardabil and other cities nearby took in many of the injured, residents and Iranian media said, and there were long queues of survivors waiting to be treated.
The U.S. Geological Survey measured Saturday's first quake at 6.4 magnitude and said it struck 37 miles northeast of the city of Tabriz, a trading hub far from Iran's oil-producing areas and known nuclear facilities.
The second, measuring 6.3, struck 11 minutes later near Varzaghan, 30 miles northeast of Tabriz.
More than 1,000 villages in the area were affected by the earthquakes, Ahmad Reza Shaji'i, a Red Crescent official, told the Iranian Students' News Agency. About 130 villages suffered more than 70 percent damage, and 20 villages were completely destroyed, he said.