The United Nations says the war in Syria has become a conflict with "countless actors and front lines" with both government forces and various anti-government fighters committing crimes against humanity.
In a new report Wednesday, the U.N. commission of inquiry on Syria highlights the effect the conflict is having on the region, saying the impact is "no longer confined to Syrian territory."
Commission chairman Paulo Pinheiro called attention to the Islamic State militants who have taken over large areas in eastern Syria as well as northern and western Iraq, saying the group "poses a clear and present danger to civilians" in areas it controls.
The report says the Islamic State's gains in Iraq have boosted its military capabilities, and that the militants are increasingly fighting other anti-government groups in Syria instead of Syrian forces.
The commission noted the international support meant to boost "moderate" opposition fighters, saying those efforts to provide money and equipment have not helped reverse the dominance of radical armed groups operating in Syria.
The report also calls attention to the lack of an enduring international push to find a resolution to the crisis, saying "influential states have turned away from the difficult work required for a political solution."
Long-sought face-to-face peace talks mediated by former U.N. envoy for Syria Lakhdar Brahimi concluded earlier this year with little progress.
Pinheiro said the fighting in Syria is continuing "with no regard to law or to conscience" as hundreds of people die every day.
The U.N. said last week that more than 191,000 people have been killed since the conflict began in March 2011.
Wednesday's report says the apparent goal of the Syrian military's operations is "to render life unbearable in areas out of its control," detailing the use of sieges followed by bombing campaigns and the arrests of men who are of fighting age.
It also says the government has used illegal chlorine gas in its attacks, and is "systematically targeting civilians and civilian infrastructure."
The commission recommends that the U.N. Security Council consider referring the crisis to the International Criminal Court, and calls on all parties to stop abuses that include murder, rape, torture and forced disappearances.