Syria may face justice at the International Criminal Court as news came that UN investigators have asked the Security Council to refer the issue. Meanwhile, the US and major European countries have urged Syria's President Bashar Assad to step down.
The call from the US President Barak Obama came in response to a deadly and protracted crackdown on anti-government protesters, with military force being used against civilians.
The leaders of France, Germany and the United Kingdom added their voices to Obama's demand.
"Our three countries believe that President Assad, who is resorting to brutal military force against his own people and who is responsible for the situation, has lost all legitimacy and can no longer claim to lead the country," British Prime Minister David Cameron, French President Nicolas Sarkozy and German Chancellor Angela Merkel said in a statement.
US Secretary of State Hillary Clinton said the United States "will take steps to mitigate any unintended effects of the (new) sanctions on the Syrian people."
"These actions strike at the heart of the regime," Clinton said, noting that the United States expects other countries "will amplify the steps we are taking."
The call for Bashar Assad to step down came despite the Syrian president’s assurances to UN Secretary-General Ban Ki Moon that military operations against anti-government protesters had been halted.
Meanwhile the UN mission, which was set up by the Human Rights Council in late April, released a 22-page report on Thursday which finds Syria guilty of human rights violations in its months-long crackdown on protesters, which it said involved the use of torture, deprivation of liberty and persecution.
"The mission found a pattern of human rights violations that constitutes widespread or systematic attacks against the civilian population, which may amount to crimes against humanity," the report says.
The UN High Commissioner for Human Rights, Navi Pillay, addressed the 15-nation UN Security Council in a closed-door session on Thursday.
Officials said Pillay was expected to give an assessment of the situation on the ground in Syria.
Diplomats expressed hope that the session would pave the way for action against Syria, including a Security Council resolution.
Walid Phares, an advisor to the Anti-Terrorism Caucus, says that if Assad does not step down and continues with his policies, Syria will be in for a very bumpy ride.
“It all depends on how President Assad will quit the power,” said Phares. “If it is of his own will, if he decides to leave, then you are going to have a process. But even that process is not going to be easy, because the international committee does not know much about the internal mechanisms of Syria. Syria did not have a regime that was open. If he quits on his own, which would be the best option for the international community, there should be a UN-sponsored initiative inside Syria.”
“But if he quits as a result of being militarily defeated, which is the less-wanted solution, then there will be a battle and he would lose this battle,” Phares declared.
However, a resolution is unlikely to pass due to the refusal of Russia, China, Brazil, India and South Africa to accept the measure.
About 2,000 people are believed to have been killed in Syria since March. However, the authorities say that the number is a substantial over-estimate.