Eight earthquakes struck Istanbul within a single hour on Wednesday, sending residents rushing into the streets and prompting officials to mobilize emergency response teams across Türkiye’s largest city.

The strongest tremor registered at 6.2 magnitude in Istanbul and occurred at 12:49 p.m. local time off the coast of Silivri district in the Marmara Sea, according to Türkiye’s Disaster and Emergency Management Authority (AFAD). The earthquake struck at a shallow depth of 6.92 kilometers.

The extraordinary sequence of tremors began at 12:19 p.m. with a 3.9 magnitude earthquake, followed by seven additional shocks throughout the hour. According to data compiled by the Disaster and Emergency Management Authority (AFAD), the subsequent earthquakes occurred in rapid succession: a 6.2 magnitude at 12:49 p.m., followed by a 5.9 and a 4.4 at 12:51 p.m., a 4.8 at 1:01 p.m., a 4.5 and a 4.9 at 1:02 p.m., and finally a 3.4 magnitude tremor at 1:07 p.m.

Authorities reported that the tremors were felt not only in Istanbul but also in surrounding provinces. The second largest earthquake measured 5.9 magnitude, while the smallest registered at 3.4 magnitude near Buyukcekmece.

Video footage from security cameras captured the moment the main earthquake struck, showing people rushing out of buildings in panic.

“There are reports from people who felt the tremor, particularly in the Silivri and Buyukcekmece areas,” said a CNN Turk reporter during live coverage. “While we are currently in Caglayan and did not feel it here, it’s reported that the earthquake was felt in districts closer to Silivri, especially in Catalca. Coastal areas seem to have experienced the tremor as well.”