GENEVA: Syria and Russian air strikes in rebel-held areas have killed 240 civilians in the past week in some of the conflict’s worst violence that may also constitute war crimes, the top United Nations human rights official said on Saturday.

Zeid Ra’ad Al Hussain, UN High Commissioner for Human Rights, said his office had received reports including video footage of possible use of “toxic agents” on February 4 in the rebel-held town of Saraqeb, Idlib province.

“After seven years of paralysis in the (UN) Security Council, the situation in Syria is crying out to be referred to the International Criminal Court, as well as for a much more concerted effort by States to bring peace,” Zeid said in a statement.

Fresh bombardment hit the Syrian rebel enclave of Eastern Ghouta on Friday, the fifth straight day of a bombing campaign that has killed more than 240 civilians.

Syrian warplanes and artillery have battered the enclave’s towns since Monday, trapping thousands of families in makeshift bomb shelters and overwhelming rescue workers.

World powers failed to back an appeal by UN officials for a monthlong ceasefire to allow for desperately needed aid deliveries and medical evacuations.

Bombardment resumed on several Eastern Ghouta towns on Friday morning, killing 13 civilians, according to the Syrian Observatory for Human Rights, a Britain-based war monitor.

At least six were killed in Douma, including two children.

“There were eight families living in this neighbourhood,” said Abu Ezzo, a 29-year-old resident of Douma.

“The aeroplane hit the houses, and every single resident came out either wounded or dead,” he said.

One of the raids hit Douma’s local civilian council, starting a fire on the upper levels.