A strong earthquake shook the Greek capital Athens on Friday, sending people rushing out of buildings and into the street. The 5.1 magnitude tremor struck 23 kilometers northwest of the capital, near Magoula, according to the Athens Institute of Geodynamics.

The Institute said there had been seven aftershocks, with the largest measuring 3.1.

Residents who contacted the European-Mediterranean Seismological Centre said the quake was strong but short, describing televisions shaking and objects falling from bookshelves.

There were no immediate reports of injuries or serious damage.

“There are no reports of serious injuries,” government spokesman Stelios Petsas told local media. “There are confirmed reports of building damage in some areas of Attica.”

Petsas added that the city’s fire brigade was evacuating people stuck in elevators and mobile networks that experienced outages in the quake were working again.

The Ministry of Citizen Protection in Athens said two helicopters were assessing the extent of damage in the area.

Greece is one of the most earthquake-prone countries in Europe due to its fault lines. The country is situated at a convergence point where three massive plates of the earth’s crust – Eurasian, Arabic and African – grind together.

In July 2017, a 6.7-magnitude quake rocked Kos, killing two people, injuring scores and causing extensive damage to the island’s historic buildings.

A major earthquake measuring 5.9 hit Greece in 1999, leaving 143 people dead.