A 6.1-magnitude earthquake in western Turkey toppled at least one building at its epicenter on Sunday evening, sending shock waves as far as Istanbul, over 120 miles away.

Many people in the cities and towns who felt the tremor fled into the streets in panic, and some scrambled to reach their loved ones. With aftershocks continuing to rattle the area, some people were staying outdoors.

The authorities warned people to avoid buildings that could be unstable. Officials released varying reports of the number of structures affected, but at least one building had collapsed according to local and national authorities.

Four people were rescued from a collapsed building in the town of Sindirgi, the epicenter, Mayor Serkan Sak told Turkish broadcasters. Crews were still working to free another person under the rubble, according to Turkey’s emergency agency, AFAD.

No deaths were reported, but the health minister said four people were being treated in hospitals for minor injuries.

Sindirgi is a small town of about 30,000 people, surrounded by mountains and in a region of forests and plains.

Turkey is crisscrossed by major fault lines that often produce strong tremors. In 2023, a 7.8-magnitude quake and its aftershocks killed more than 50,000 people in 11 eastern and southeastern Turkish cities and about 6,000 more in neighboring Syria.

Scientists for years have been warning that earthquakes in Turkey could be especially deadly because of shoddy construction and the abundance of old buildings not built to modern standards to withstand disasters.