Syria and Turkey has already exceeded 800 death people.

Search and rescue teams have been dispatched to the south of the country, Turkey's interior minister, Suleyman Soylu, said. AFAD, the disaster agency, said it had requested international help through the Emergency Response Coordination Centre (ERCC), the European Union's humanitarian program.

Nearly 1,000 search and rescue volunteers have been deployed from Turkey's largest city, Istanbul, along with dogs, trucks and aid, according to its governor, Ali Yerlikaya.

"Sorry for our loss. I wish our injured a speedy recovery," Yerlikaya wrote on Twitter.

The governor of Gaziantep, Davut Gul, said on Twitter that "the earthquake was felt strongly in our city," and advised the public to wait outside their homes and stay calm.

"Please let's wait outside without panic. Let's not use our cars. Let's not crowd the main roads. Let's not keep the phones busy," he said.

Gaziantep province has a number of small- and medium-sized cities, with a sizable refugee population, according to Brookings Institute fellow Asli Aydintasbas.

"Some of these areas are rather poor. Some are more richer, urban areas ... but other parts that we're talking about that seem to have been devastated, are relatively lower income areas," she said.

Video from the city of Diyarbakir, to the northeast of Gaziantep, shows rescue workers frantically trying to pull survivors out of the rubble.

Turkish President Recep Tayyip Erdogan said the quake was felt in many parts of the country.

"I convey my best wishes to all our citizens who were affected by the earthquake that occurred in Kahramanmaraş and was felt in many parts of our country. All our relevant units are on alert under the coordination of AFAD," Erdogan wrote on Twitter