Story highlights Report accuses "the highest levels of Syria's government" of war crimes

Rebels are also implicated in the commission of war crimes, report says

War crimes in Syria are "very serious crimes ... crimes against humanity"

The majority of people have been killed by conventional weapons, not chemical ones

A United Nations fact-finding team has found "massive evidence" that the highest levels of the Syrian government are responsible for war crimes in the nation's long-running civil war, the U.N.'s human rights chief said Monday.

Navi Pillay didn't name President Bashar al-Assad, but she said the evidence collected by the U.N. Commission of Inquiry on Syria implicates the regime's top man.

The panel's members have "outlined their view that the facts point to the commission of very serious crimes, war crimes, crimes against humanity," Pillay, the U.N. high commissioner for human rights, told reporters in Geneva, Switzerland. "They point to the fact that the evidence indicates responsibility at the highest level of government, including the head of state."

Still, Pillay declined to say whether al-Assad was named in a list of suspects that the panel produced. The list is confidential -- not to be released until the matter goes from the fact-finding stage to a formal international investigation -- and even she has not read it, she said.

Pillay said the evidence also shows that rebels have committed war crimes and pointed to the fact that the majority of deaths -- more than 100,000 since the civil war began in 2011 -- are from unlawful attacks with conventional weapons, not from chemical weapons, which have gotten much of the attention in recent months.

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A joint Organisation for the Prohibition of Chemical Weapons-United Nations team charged with overseeing the destruction of Syria's chemical weapons began inspecting sites in October. The U.N. Security Council resolution that authorized the mission set a deadline of mid-2014 for Syria to destroy its chemical weapons or face consequences.

The goal is to move the most dangerous chemicals out of the country as quickly as possible, said Sigrid Kaag, head of the joint team.

But the presence of chemical weapons inspectors has not stopped the influx of conventional weapons into Syria's civil war. As recently as September, U.S. officials confirmed that they sent artillery described as light weapons, some anti-tank weapons and ammunition to Syrian rebels, and Russia has long supplied arms to the Syria's government.

Pillay called on U.N. member states to refer the report to the International Criminal Court, a move that might be blocked by the U.N Security council, where Russia and China have so far blocked efforts that could punish the Assad regime.