A total of 59,648 people were killed in Syria between March 15, 2011 and Nov 30, 2012, according to an exhaustive analysis carried out by data specialists on behalf of the UN Human Rights Office.
A gunman keeps watch. Photo: AFP
"Given there has been no let-up in the conflict since the end of November, we can assume that more than 60,000 people have been killed by the beginning of 2013," Pillay said.
"The number of casualties is much higher than we expected, and is truly shocking," he said.
Earlier reports said up to 30,000 people have been killed in the conflict between government forces and the opposition, which comprises many groups, from Communists and secular liberals to Islamist groups, including Al Qaeda.