The U.S. Geological Survey (USGS) initially put the magnitude of the quake at 5.9 but revised this later to 5.5.
Pirhossein Koulivand said all but one of the 75 injured had been released after treatment following the earthquake in Gilan Gharb in Kermanshah province, according to the emergency services' website.
In November, a 6.3 magnitude earthquake shook western Iran, injuring more than 700 people, with most suffering minor wounds.Iran sits astride major fault lines and is prone to frequent tremors. In 2003, a 6.6 magnitude quake in southeastern Kerman province killed 31,000 people and flattened the historic city of Bam.