PARIS - The United Nations Educational, Scientific and Cultural Organization (UNESCO) on Tuesday expressed concerns over damage to Syrian and Turkish heritage sites, and vowed support for the two earthquake-devastated countries.

Following an initial survey of damage to heritage carried out alongside national authorities, UNESCO said: "In Syria, UNESCO is particularly concerned about the situation in the Ancient city of Aleppo, which is on the List of World Heritage in Danger."

Significant damage had been noted in the citadel, UNESCO said. The western tower of the old city wall had collapsed, and several buildings in the souks had been weakened. Meanwhile, in Turkiye, several buildings in the city of Diyarbakir have collapsed.

The city is home to the World Heritage site "Diyarbakir Fortress and Hevsel Gardens Cultural Landscape", an important center for the Roman, Sassanid, Byzantine, Islamic and Ottoman periods.

UNESCO's experts, with the cooperation of national authorities, are trying to establish a precise inventory of the damage to sites on the World Heritage List.

"My condolences go out to the families and loved ones of those who died. My thoughts are also with the injured and all those affected. Our Organization will provide assistance within its mandate," said Audrey Azoulay, UNESCO's Director-General.

A powerful magnitude 7.7 earthquake struck Turkiye's southern province of Kahramanmaras at 4:17 am local time (0117 GMT) on Monday, followed by a magnitude 6.4 quake a few minutes later in the country's southern province of Gaziantep, and a magnitude 7.6 earthquake at 1:24 pm local time (1024 GMT) in Kahramanmaras.

The death toll in Turkiye climbed to 5,434 on Tuesday, while the number of people injured rose to 31,777, Turkish Health Minister Fahrettin Koca said.

According to figures released by the Syrian Health Ministry on Tuesday, 812 people were killed and 1,449 others injured in Hama, Aleppo, Latakia, and Tartous provinces, and the rebel-held area in Idlib province.

A Chinese rescue team departed from Beijing for Turkiye on a chartered plane on Tuesday afternoon, to join earthquake relief efforts in the country.