Ebrahim Kalantari / AFP/Getty Images
Iran has suffered a 6.1 magnitude earthquake, the US Geological Survey says.
The quake, which struck at 21:38 local time (00:38 GMT), reportedly killed one person and injured 141, while the damage was limited.
The epicentre was in the Zagros Mountains in the West Azerbaijan province, west of the city of Ahvaz.
Iran has been struck by a number of earthquakes in recent years.
One of the deadliest of these was in 2003, when around 31,000 people were killed and more than 300,000 injured in the Kerman province in southern Iran by an earthquake measuring 7.7 on the Richter scale.
In 2016, a magnitude 6.3 earthquake killed 120 people in the north-western province of Gilan, while in 2016, a magnitude 5.9 quake hit the city of Davud.
The country is built on a huge, loosely-constructed ring of plate boundaries – volcanic regions of mountains where the tectonic plates give way.
The landmass changes a lot during the passage of magma, which rises to the surface after the near-vacuum of earth’s crust has exhausted itself. The rocks of the tectonic plates join around the border of West Azerbaijan, in south-western Iran.
This last subduction zone has produced earthquakes for millennia. The tremors are so powerful that they have left scars in the earth’s crust. For example, the Iran-Iraq fault, which crosses Iran from west to east, has a history of more than 10,000 faults. This means that the area sits on one fault or another at all times.