Syrian forces and allied "shabbiha" militia who stand accused of committing a massacre in Houla
may be liable for prosecution for crimes against humanity, UN High Commissioner for Human Rights Navi Pillay said on Friday.
The UN estimates that over 13,000 people were killed since the Syrian
uprising began, in March 2011.
Pillay, in a speech read out on her behalf to a special session of the United Nations Human Rights Council, said: "These acts may amount to crimes against humanity and other international crimes and may be indicative of a pattern of widespread or systematic attacks against civilian populations that have been perpetrated with impunity."
Pillay, a former war crimes judge, added: "I reiterate that those who order, assist or fail to stop attacks on civilians are individually criminally liable for their actions."
The international community backed its condemnation of the ongoing carnage in Syria with a coordinated and harsh diplomatic move, as on Tuesday the United States, Britain, France, Germany, Italy, Spain, Bulgaria, Canada and Australia expelled the Syrian envoys stationed in the respective capitals.
AP contributed to this report