Turkish Interior Minister Süleyman Soylu said six people were killed and 294 were taken to hospital.
Monday’s quake hit the Turkish town of Defne at 8:04 pm (1704 GMT) and was strongly felt by AFP teams in Antakya city. It was also felt in Lebanon.
Turkey’s disaster management agency said on Twitter another 5.8-magnitude quake followed three minutes later and its epicenter was Samandağ district in Hatay.
The agency recorded two more tremors of 5.2 magnitudes around 20 minutes after the first on Monday.
Images from the DHA news agency showed a hospital in Antakya being evacuated.
DHA said patients in an intensive care unit were taken by ambulance to field hospitals to continue their treatment.
Soylu said rescue workers were trying to find people trapped under rubble.
The walls of badly damaged buildings crumbled while several people, apparently injured, called for help.
On a street in Antakya, Ali Mazlum, 18, told AFP: “We were with (disaster response agency) AFAD who were looking for the bodies of our family when the quake hit.
“You don’t know what to do… we grabbed each other and right in front of us, the walls started to fall. It felt like the earth was opening up to swallow us up.”
Mazlum, who has lived in Antakya for 12 years, was looking for the bodies of his sister and her family as well as his brother-in-law and his family.
Officials had urged people to stay away from the coast but Vice President Fuat Oktay said the warning had been lifted as the risk of a tsunami had passed.
“The road moved like waves. The building moved back and forth, the cars moved left to right. It knocked me off my feet,” said Mehmet Irmak, who works at a notary’s office.
“Hatay is no longer a safe place. We could hear a lot of buildings collapsing… We will wait for a new day, but I don’t know what I’m going to do,” added Irmak, who had been sleeping in his car for two weeks after the first quake.
According to AFAD, more than 6,200 aftershocks have been recorded since the 7.8-magnitude hit Turkey and Syria, leaving millions homeless.
Officials said after the February 6 quake that aftershocks would be felt for a year because of the force of the first tremor.
That earthquake killed 41,156 people in Turkey and 3,688 in Syria, but experts expect the toll to rise as the rubble is cleared and rescue operations end.
Eleven provinces were hit by the previous tremors and on Sunday, officials said rescue operations continue only in two: Hatay and Kahramanmaraş.
“My thoughts continue to be with the people of Turkiye and Syria, as they face the impact of new earthquakes striking the region this evening,” wrote U.N. chief Antonio Guterres on Twitter.
U.N. teams there “are assessing the situation, and we stand ready to provide additional support as needed”, he added.
