A day of airstrikes in the Syrian enclave of Eastern Ghouta killed at least 17 civilians and damaged 10 medical facilities, according to groups working in the region.
The White Helmets volunteer rescue group reported dozens of airstrikes in the area on Saturday, saying that four children were among the dead and 40 more people were injured.
It said government airstrikes, backed by Russian air power, had begun nine days ago. The latest strikes come as the government steps up its offensive against the country's last rebel-held areas.
A resident in Eastern Ghouta told CNN that airstrikes and shelling were continuing Sunday, adding that he heard four airstrikes in the space of 10 hours.
The UK-based Syrian Observatory for Human Rights, a monitor of the conflict, also reported the death toll of 17, adding that Syrian and Russian aircraft had targeted several residential areas. The monitor said that a coalition of rebels and jihadists had surrounded the only Syrian-regime base in the enclave several days ago.
Video provided by the White Helmets shows rescuers digging through mounds of rubble to reach a man, and in a separate video, they dig to recover a little girl.
In other footage, residents are heard screaming as they try to escape heavily damaged buildings, and the injured are seen being laid on stretchers and loaded into the back of vans to be taken away for treatment.
10 medical facilities hit
But treatment now is becoming increasingly difficult to find in Eastern Ghouta, and other areas where rebel groups are still trying to hold ground.
At least 10 medical facilities, including a crucial women and children's hospital, have also been hit by airstrikes and artillery shelling over a nine-day period in Eastern Ghouta, and the provinces of Idlib and Hama, the Union of Medical Care and Relief Organizations said, calling the attacks "sickening and unacceptable."
The UN said that the women and children's hospital in Idlib, the largest-remaining rebel-held area, had been repeatedly taken out of service.
"For the third time in less than a week, the Maternity and Pediatric Hospital in Ma'arrat An Nu'man... (Idlib) had been damaged and taken out-of-service. Such actions are utterly unacceptable and must stop," wrote UNOCHA, which coordinates the humanitarian response in Syria, on Twitter Saturday.
Eastern Ghouta, Idlib and Hama have all been designated "de-escalation zones" as part of an agreement brokered by Russia, Turkey and Iran aimed to reduce violence in remaining rebel-held territory for at least six months. Fighting and airstrikes in those areas violate a truce proposed by Russia, which was accepted by Syrian President Bashar al-Assad in November.
Rebels took full control of Idlib province, which borders Turkey, in 2015.
Violence erupted in Eastern Ghouta, which sits on the outskirts of the Syrian capital, Damascus, several weeks ago, and airstrikes have resumed there.
Eastern Ghouta area was seized by rebel groups after the Syrian civil war erupted with the Arab Spring, but it has been besieged by government forces since 2013.
The regime's chokehold on the enclave has led to a desperate humanitarian situation there, with the government repeatedly refusing aid into the area or to allow civilians to easily leave.
In late December, however, the government allowed more than 80 people to leave Eastern Ghouta to be taken to hospitals in Damascus for medical treatment, in a one-off people swap deal, in which prisoners were swapped for critically ill civilians.
A critically ill six-month old baby died while waiting to be evacuated, according to Mohamad Katoub, advocacy manager for the Syrian American Medical Society.