The death toll in Syria from the magnitude 7.8 earthquake that hit southeastern Türkiye Monday climbed to nearly 1,600 on Tuesday, according to figures compiled from multiple sources.

The quake-damaged area in Syria is divided between the Bashar Assad regime-held territory and the country's last opposition-held enclave, which is surrounded by government forces and borders Türkiye.

While the Syrian Health Ministry reported casualties in areas under the regime's control, the Syrian Civil Defense was reporting casualties in the opposition-held areas.

The death toll in government-held areas of Syria climbed to 656 people, with some 1,400 injured, according to the Health Ministry.

In the country's opposition-held northwest, groups that operate there said at least 450 people died, with many hundreds injured.

Time is running out to save hundreds of families still trapped under the rubble of destroyed buildings after the devastating earthquake, the head of the Syrian opposition-run civil defense service said Tuesday.

Raed al-Saleh told Reuters that urgent help was needed from international groups for the rescue effort by the organization known as the White Helmets in rebel-held northwest Syria, where hundreds were killed and injured.

The war-ravaged country called on the United Nations and all member states to help with rescue efforts, health services, shelter and food aid.

Syria's U.N. Ambassador Bassam Sabbagh told reporters the U.N. secretary-general "assured us that the U.N. will do all it's possible in helping Syria in this very difficult situation." Sabbagh said he had delivered a letter to Guterres from the country's foreign minister requesting help.

Sabbagh was asked whether Syria would agree to allow the U.N. to deliver aid through other crossing points from Türkiye, if feasible.

He didn't respond directly but said the government is ready to help and coordinate aid deliveries "to all Syrians in all territory of Syria."

The opposition-held territory has depended on a flow of aid from nearby Türkiye for everything from food to medical supplies.

Earlier Monday, strong tremors rocked Idlib, Aleppo, Hama, Latakia, and Raqqa regions of Syria, according to the state-run SANA news agency.

Dozens of buildings were also destroyed or damaged in opposition-held areas in northern Syria, where rescue teams are frantically searching for survivors.

Over 3,381 people have died so far in Türkiye in the two magnitude 7.7 and 7.6 earthquakes, according to Türkiye’s Disaster and Emergency Management Authority (AFAD).

According to the agency, both earthquakes originated in the southern province of Kahramanmaraş.