The Kandilli seismology center in Istanbul said the quake struck at 5:22 a.m. local time about 25 miles (40 km) north-northwest of Sanliurfa (Urfa).
Shaking was felt most strongly in the town of Samsat, in Adiyaman province.
The Anatolian Agency reports that residents ran out of their homes and remained in the streets long after the shaking stopped. The quake was also felt in neighboring provinces.
Earthquakes are a common occurrence in Turkey, which lies on active tectonic fault lines.
Two quakes devastated parts of the country in 1999, killing more than 18,000 people.
