As the United Nations unveiled a new report on Monday accusing not only "Islamic State" (IS) terrorists but the government in Damascus of war crimes, the US and Russia were announcing a possible ceasefire in the five-year conflict.

"Flagrant violations of human rights and international humanitarian law continue unabated, aggravated by blatant impunity," wrote the UN Independent International Commission of Inquiry in its new report.

According to the panel, both sides have employed starvation, indiscriminate targeting of civilians, and blocking of humanitarian aid delivery as tools of war.

"Government forces, anti-government armed groups and terrorist organizations employ sieges and consequent starvation, denial of humanitarian access and other forms of deprivation as instruments of war to force surrender or to extract political concessions," the report said, warning that the state is on the brink of complete collapse.

Ceasefire back on track

Meanwhile, Washington and Moscow said that a new truce agreement had been finalized and would take effect on Saturday. Although major problems remained about enforcing the ceasefire and contingency plans if the deal should be violated, an alliance of rebel factions has said it will support it.

A formal announcement was expected after Presidents Barack Obama and Vladmir Putin finished a telephone call discussing the matter.

While officials declined to offer too many details of the agreement, they did say that it did not include stopping attacks on terrorist targets like those belonging to the IS, al-Nusra or al-Qaeda jihadist groups.

Omar Osso, a member of the parliament under Syrian President Bashar al-Assad, cast some doubt on the peace deal, however, telling the Associated Press that he was "not optimistic that clashes will stop because we are dealing with criminals who have hundreds of state sponsors."

Osso, who was part of the team representing the Assad regime in failed ceasefire talks in Geneva earlier this month, added the caveat that a truce could be "relatively successful" in some areas of the country.

es/rc (AP, Reuters)