The quake struck near the Mosha Fault, one of Iran’s most active seismic zones, according to Iranian media and the country’s seismological centre.

The earthquake occurred at a depth of 10 kilometres (6.21 miles), the centre said.

Residents in several areas rushed out of homes and buildings following the tremors, though authorities said there were no immediate reports of casualties or major damage.

Iran’s state broadcaster IRIB said the quake struck the border area between Tehran and Mazandaran.

Iranian media reported that several earthquakes were felt in eastern parts of Tehran province during the night, with experts describing the sequence of tremors as unusual for the region.

Seismologist Yat Mehdi Zare said it remained unclear whether the activity reflected a release of underground energy that could reduce future risks or a warning sign of stronger seismic movement near Tehran.

He warned that Tehran’s dense population, urban sprawl, weak infrastructure and heavy traffic could worsen the impact of even moderate earthquakes and complicate emergency response efforts.

Tehran, home to more than 14 million people, lies close to several major fault systems, including the North Tehran, Mosha and Ray faults.

Iran is among the world’s most earthquake-prone countries and still carries memories of the devastating 2003 Bam earthquake, which killed more than 30,000 people.