The first quake had a magnitude of 7.8 and occurred at a depth of 17.9 kilometers at 04:17 local time.
The epicenter was about 33 kilometers from the provincial capital Gaziantep and 26 kilometers from the city of Nurdagi, located in the southeastern part of the country.
The second quake, with a magnitude of 6.7, occurred at 04:28 at a depth of 9.9 kilometers.
The quake was also felt in Lebanon, Syria and Cyprus, according to the AFP news agency’s correspondents.
According to the AP news agency, buildings in Beirut and Damascus were said to have been shaken by the quake and people fled into the streets.
Turkish authorities have not yet reported any deaths or injuries from the quake, but videos posted on social media show destroyed buildings in several cities in southeastern Turkey.
State-controlled media in Syria report that buildings have collapsed in the city of Aleppo and in the city of Hama.