A 6.1 magnitude earthquake has struck 89 kilometers from Mashhad, Iran’s second most populous city, the US Geological Survey reported, adding that the tremor had a been registered at a shallow depth of 10 kilometers.

Afghan Voice Agency(AVA),The quake hit northeastern Iran, 89 kilometers from the city of Mashhad, which has a population of over 2.3 million people.

There have been no reports of casualties or damage so far.

Four tectonic plates (Arabia, Eurasia, India, and Africa, Anatolia) are responsible for seismic activity in the region, USGS said. In particular, the collision of the Arabian and Eurasian plates “causes crustal shortening” in the Alborz and Kopet Dag Mountains in northern Iran, which leads to earthquakes, it added.