A moderately strong earthquake with a preliminary magnitude of 4.7 shook central Turkey.
There are no immediate reports of any injury or damage.
The Istanbul-based Kandilli Observatory said the quake occurred at 6.01am local time (4.01am Irish time), in the central province of Sivas.
Earthquakes are frequent in Turkey, much of which lies on the North Anatolian fault.
In 1999, two powerful earthquakes struck northwestern Turkey, killing about 18,000 people.