The United Nations Human Rights Council has strongly condemned the violence in Syria and is to appoint a special investigator on the crackdown on anti-government protesters there.
A resolution described by some diplomats as the toughest ever passed by the council was approved at an emergency meeting in Geneva, Switzerland, by 37 votes in favour to four against, with six abstentions.
Those voting against included Russia and China, which have resisted moves for a UN Security Council resolution on Syria, lest it lead to military intervention like the one in Libya.
The resolution demands the suspension of security forces suspected of violations and the release of prisoners of conscience.
However, some human rights groups are disappointed the council did not make a clearer call for referring Syria to the International Criminal Court (ICC), as council head Navi Pillay had wanted.
Opening the meeting, Ms Pillay had said Syrian president Bashar al-Assad should be referred to the International Criminal Court.
"All acts of murder, torture and other forms of violence must be stopped immediately," Ms Pillay said. "All prisoners of conscience and those arbitrarily detained must be released, and acts of reprisal against human-rights defenders must end."
The council was told that last month alone, 56 children were killed as Syrian security forces continue to try to suppress the pro-democracy movement that arose nine months ago.
The UN estimates that since the crackdown began, more than 4000 people have been killed; but Ms Pillay says reliable information indicates the death toll is much higher than that.
She says the ruthless repression is driving Syria into full-fledged civil war, as rebel soldiers and others take up arms against the government.
US imposes fresh sanctions
The United States government is vowing to do whatever it can to hasten the democratic transition in Syria, imposing fresh sanctions on two high-ranking Syrians and two government-controlled firms.
Washington's efforts come after the European Union imposed fresh sanctions on the Syrian government.
During a congressional hearing on Iran, the under-secretary for political affairs, Wendy Sherman, told senators she is confident a change is coming to Syria.