The UN human rights chief has called on the Syrian regime to halt its "assault on its own people."
Navi Pillay, the UN High Commissioner for Human Rights, urged the Syrian regime to allow her fact-finding mission to investigate all allegations of rights violations.
She said her office has received reports that the number of people killed in a crackdown on protesters against President Bashar al-Assad's regime since March has exceeded 1,100, with up to 10,000 detained.
About 1,600 Syrians have fled to Turkey in recent days amid fears of an imminent crackdown in northern Syria.
Pillay called on Syria's neighbors to keep their borders open for refugees fleeing Syria.
Turkish Foreign Minister Ahmet Davutoglu meanwhile told a meeting of the Contact Group on Libya in Abu Dhabi that some 2,400 Syrian refugees have crossed into Turkey.
compiled from agency reports