Several people have been reported injured, when strong earthquake struck in northwestern Turkey.

Turkish Interior Minister said that 22 people were being treated at hospitals, some of whom were said to have leapt from balconies or windows, fearing their buildings might collapse. He added that at least one person was in “serious condition,” though offered few other details about those injured.

There were no immediate reports of major structural damage.

According to Turkey’s Disaster and Emergency Management Presidency, the earthquake rocked the country’s northwestern Duzce province early Wednesday morning, centering on the town of Golkaya.

Powerful 6.1-magnitude quake was felt some 125 miles east in Turkey’s largest city of Istanbul.

Während de US Geologësch Ëmfro (USGS) recorded a 6.1-magnitude quake, local disaster officials measured the primary tremor at 5.9, while the European-Mediterranean Seismological Centre (EMSC) reported 6.0-magnitude earthquake that struck at a depth between 2 and 10 kilometers (1.2 to 6.2 miles).

According to official reports, the first tremor was followed by at least 35 smaller aftershocks, triggering panic as many people rushed out of buildings in the earthquake-prone region.

Huge earthquake killed some 800 people in Duzce province in 1999, which was preceded by another tremor in nearby Kocaeli province the same year, which left 17,000 dead.