The shallow quake hit 26 kilometres (16 miles) southwest of the city of Javanrud in Kermanshah province, USGS said.

In its initial assessment, the USGS issued a yellow alert for quake-related fatalities, saying "some casualties are possible and the impact should be relatively localised."

Iran sits on top of two major tectonic plates and sees frequent seismic activity.

In November last year a major 7.3-magnitude quake killed 620 people in Kermanshah province and another eight people in Iraq.