In some of the areas most affected by the country's decade of conflict, health infrastructure is insufficient while basic medical supplies and vaccine doses are in short supply.

While the number of cases is spiking across the country, the areas that seem worst hit by the pandemic's latest wave are those in the north that still escape government control.

In the Idlib region, where around half of the more than three million residents were displaced by conflict, the number of recorded daily infections has increased sharply and now often tops 1,000 a day.

"From August to September the confirmed number of coronavirus cases in northwest Syria jumped by 144 percent to 71,715 as of 28 September with 1,151 deaths," Save the Children said.

The charity said only a dozen beds in intensive care units remained for the entire region and called for emergency international assistance to avert an even bigger disaster.

"One death from coronavirus is one too many, but to hear that a baby and a 17-year-old have also been claimed is devastating," said Sonia Khush, the NGO's Syria response director.

"The world must not look away," she said.

- 'Uncontrolled' -

Francisco Otero Y Villar, Syria head of mission for the medical charity Medecins Sans Frontieres (Doctors Without Borders - MSF), described the situation in the northwest as an "uncontrolled outbreak".

"Hospitals are saturated, patients are waiting in lines to get a bed in intensive care units," he told AFP.

He explained that the region's limited oxygen production was another impediment and that low vaccination rates could allow the virus to spread more.

Otero Y Villar said the percentage of people in the entire northwestern Syria region who been vaccinated stood at a lowly 2.6.

The Syrian health ministry said last week that hospitals in Damascus and in the main coastal city of Latakia had reached full capacity.

The ministry said that the rise in numbers was at least in part due to increased testing.

But low testing and a lack of transparency by the authorities across Syria mean that deaths and infections have most likely been grossly under-reported since the start of the pandemic.

Covid-19 cases are also increasing in the country's northeast, which is mostly controlled by an autonomous Kurdish administration, and in government areas.

Jawan Mustafa, who heads the Kurdish administration's health department, said only 55,000 vaccine doses had been received by the region.

"The situation will get out of control if the administration does not receive sufficient support. It cannot face this pandemic alone and it is spreading fast," he said.