The USGS reported another 6.7 magnitude quake with an epicenter near the first one about 15 minutes later with a depth of 9.9 kilometers.
The southern region of Gaziantep is a major industrial and manufacturing center of Turkey.
Turkey is located in one of the most active seismic zones in the world.
In August 1999, a magnitude 7.4 earthquake struck the northwest of the country, killing 17,000 people.
Experts have long warned that a major quake could devastate Istanbul, which has allowed widespread construction without safety precautions.
A 6.8 magnitude earthquake struck Elazig in January 2020, killing more than 40 people.
And in October of that same year, another magnitude 7.0 shook the Aegean Sea, causing 114 deaths and more than 1,000 injuries.
