At least 1,504 people have been killed in Turkey and Syria, and thousands more injured, after a powerful 7.8 magnitude earthquake rocked southern Turkey early Monday.

In Syria, a total of at least 592 people have died, including 371 mostly in the regions of Aleppo, Hama, Latakia and Tartus, according to the Syrian state news agency SANA, which also reported 1,089 injuries.

Meanwhile, the "White Helmets" group, officially known as the Syria Civil Defense, also reported at least 221 deaths and 419 injuries in opposition-controlled areas of northwestern Syria.

“Hundreds remain trapped under rubble,” the White Helmets added on Twitter.

In Turkey, at least 912 people have died and 5,385 people were injured, Turkey's President Recep Tayyip Erdoğan said in a televised address Monday.

Rescuers are working through the rubble of collapsed buildings to locate survivors, while NATO, the EU and 45 countries have offered assistance following the disaster.