Iran's main news channel said the quake hit the towns of Ahar, Haris and Varzaqan in East Azerbaijan province at 4:53 p.m. local time (GMT 12:23), also damaging hundreds of homes.
The TV quoted Khalil Saei, local Crisis Committee chief, as saying that 30 people were killed in Ahar, 40 in Varzaqan and 17 others in Haris.
The broadcast said at least 60 villages sustained damage ranging from 50 to 80 percent, while 4 other villages had been totally leveled to the ground.
The TV said at least three aftershocks - measuring 6.0, 4.7 and 4.1 - jolted the same area and were felt in a wide region near the Caspian Sea.
Iran is located on seismic fault lines and is prone to earthquakes. It experiences at least one earthquake every day on average, although the vast majority are so small they go unnoticed.