Navi Pillay, the United Nations high commissioner for human rights, has cited the increasing casualty count in Syria as a basis for an International Criminal Court investigation into war crimes in the nearly two-year-long conflict.

Speaking after a closed meeting of the United Nations Security Council on Friday, Pillay said there was little indication the 15-member body would take action on the 22-month conflict.

"I firmly believe that war crimes and crimes against humanity have been committed, are being committed, and should be investigated," Pillay said citing the UN figure of 60,000 deaths in Syria.

Speaking to Al Jazeera, Pillay, said the 60,000 death toll was "a conservative figure". The United Nations also estimates that by June, there could be 1.1 million Syrian refugees in the region, double the current figure of 540,000.

"I have urged the Security Council to refer the situation to the International Criminal Court for investigation of war crimes and crimes against humanity on the part of all parties engaged in this conflict," she added.

Pillay said people in Syria "see the situation as the United Nations not carrying out its responsibility to protect victims".

Syria is not an ICC member and the Security Council is the only body which can refer the conflict to the court.

Russia and China have used their power as permanent members of the Security Council to block three resolutions that would have threatened sanctions against Bashar al-Assad, the Syrian president, and in some cases a war crimes case.

Opposition fighters have also been accused of committing abuses against regime loyalists and forces. In August, an online video purported to show opposition fighters executing Assad loyalists in Aleppo.

Diplomats at the council meeting said there was discussion of the calls for an ICC investigation, but still faced opposition from Russia and its allies.