A magnitude 5.9 earthquake has hit a town in northwest Turkey, causing widespread panic but there was no immediate report of major damage, Turkey's Disaster and Emergency Management Presidency says.
The earthquake on Wednesday was centreed in the town of Golkaya, in Duzce province, some 200 kilometres east of Istanbul.
It struck at 4.08am and was felt in Istanbul, in the capital Ankara and other parts of the country.
At least 35 aftershocks were recorded.
The quake woke people from their sleep and many rushed out of buildings in panic in the province that has experienced earthquakes in the past. Power in the region was cut.
Interior Minister Suleyman Soylu said 22 people were being treated in hospitals for injuries sustained during the panic, including from jumping from balconies or windows. One of them was in serious condition, he told private NTV television.
Schools in the region were being closed as a precaution.
About 800 people were killed in a powerful earthquake that hit Duzce on November 12 1999. In August of that year, 17,000 people were killed by another powerful tremor which devastated nearby Kocaeli province and other parts of northwest Turkey.
Turkey sits on top of major fault lines and is frequently shaken by earthquakes.
