United Nations human rights investigators have in their latest report on the Syria conflict accused both sides of committing war crimes.
The report, covering the period of May 15-July 15, accused Syrian government troops of massacring civilians, bombing hospitals and committing other war crimes in their bid to recapture territory from rebel hands in recent months.
Opposition forces, including foreign fighters, have committed war crimes including executions, hostage-taking and shelling civilian neighborhoods, the report added.
The report states that evidence confirms that at least eight massacres have been perpetrated in Syria by President Bashar Assad's regime and supporters and one by rebels over the past year and a half.
"The perpetrators of these violations and crimes, on all sides, act in defiance of international law. They do not fear accountability. Referral to justice is imperative, " the U.N. commission of inquiry, led by Brazilian Paulo Pinheiro, said.
The independent experts said they had received allegations about the use of chemical weapons "predominantly by government forces."
"On the evidence currently available, it was not possible to reach a finding about the chemical agents used, their delivery systems or the perpetrators. Investigations are ongoing," the report said.
A team of 20 investigators carried out 258 interviews with refugees, defectors and others, in the region and in Geneva, including via Skype, for their 11th report in two years. They have never been allowed into Syria despite repeated requests.
The report called for a political solution to Syria's civil war and urged other states to "stop weapons transfers in view of the clear risk that they will be used to commit serious violations of international law."
Al Jazeera and wire services