More than 700 people were injured in a 6.4-magnitude earthquake that shook western Iran, state television reported in an updated toll on Monday.

The quake struck Kermanshah province late on Sunday, with an epicentre 17 kilometres (11 miles) southwest of the city of Sarpol-e Zahab, according to the country's institute of geophysics.

State television, citing the emergency services, said that 716 people had been injured, but there were no reports of deaths or major damage.

State TV showed images of cracked walls inside homes, but said only 33 of those injured remained in hospital on Monday morning.

The initial quake, around seven kilometres deep, was followed by several aftershocks including one with a magnitude of 5.2.

Morteza Salimi, an official with Iran's Red Crescent Society, said most of Sunday's casualties had been injured in a stampede sparked by the first tremors.

AFP journalists reported feeling the quake as far away as Baghdad in neighbouring Iraq.

Salimi told semi-official news agency ISNA on Sunday that the quake had rocked areas newly rebuilt after a 7.3-magnitude tremor last November that killed 620 people and injured thousands more.

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

In 2003, a 6.6-magnitude tremor struck the southeast of the country, decimating the ancient mud-brick city of Bam and killing at least 31,000 people.

The country's deadliest such incident was a 7.4-magnitude quake in 1990 that killed 40,000 people in northern Iran, injured 300,000 and left half a million homeless.