At least 2,600 people have been killed in the unrest in Syria since popular protests first broke out in mid-March, the UN human rights commissioner Navanethen "Navi" Pillay said Monday.
"With regard to Syria, let me note that, according to reliable sources on the ground, the number of those killed since the onset of the unrest in mid-March 2011 in that country, has now reached at least 2,600," Pillay told the UN Human Rights Council.
In August, the UN High Commissioner for Human Rights had told a special meeting of the council that more than 2,200 people have been killed in Syria's anti-government protests.
Syria's opposition leaders on Sunday rejected an Arab League-proposed truce plan saying that the initiative is not in touch with reality because it gives President Bashar al-Assad until June 2014, the end of his current term, to step down.
The six-nation Gulf Cooperation Council (GCC) issued a statement urging Syria to immediately stop its "killing machine" against anti-regime protesters.
Meeting in Jeddah in Saudi Arabia, the GCC also urged "the immediate implementation of serious reforms that meet the aspirations of the Syrian" people.
The UN announcement and Arab League truce-plan come on the heels of last week's declaration of 'a state of war' in Syria by Assad leading many to conclude the violence in the country will only escalate.
Also on Monday, forces loyal to Assad launched a series of raids around the protest-city of Hama. Security forces blocked all roads leading to the area and cut electricity and telephone lines.