The UN Human Rights Council (HRC) has launched a new commission of inquiry into Syria's crackdown on anti-government protesters, including possible crimes against humanity.
The announcement came as rights activists on Tuesday claimed that 18 more people have been killed in the country over the past 24 hours, including seven in the city of Homs.
By 33 votes in favour to four against and nine abstentions, the HRC passed a resolution to "urgently dispatch an independent international commission of inquiry... to investigate violations of international human rights law in Syria since July 2011".
"The resolution is adopted," Uruguay's ambassador Laura Dupuy Lasserre who chairs the council, announced after the vote.
The remaining countries on the 47-nation council abstained or were absent. China and Russia said they opposed the measure as unnecessary intervention.
Fayssal al-Hamwi, the Syrian Ambassador, called the action "100 per cent political".
The security crackdown continued in key areas across the country, Al Jazeera's Nisreen el-Shamayleh said, reporting from Ramtha on the Jordan-Syria border on Tuesday.
"We undersand that at least 55 tanks are currently raiding the town of al-Khowria in Deir ez-Zor. These tanks are shelling some of the neighbourhoods there," Shamayleh said.
"We also heard that some of the soldiers reportedly descended from two helicopters down to al-Khowria in that neighbourhood. An attack is ongoing there.
"We have also understood that the troops are destroying the homes and burning them and many arrests were made and the residents protested the attacks by taking to the streets."
Meanwhile, Robert Ford, the US ambassador to Syria, made a surprise visit to Jassem, an area in the southern Deraa province which has seen some of the worst violence.
Ford angered Damascus seven weeks ago when he paid a visit to Hama in a gesture of solidarity with the city where huge anti-Bashar al-Assad protests occurred in June and July.
Sanctions draft targets Assad and family
Western nations have circulated a draft UN resolution that calls for sanctions against the Syrian president, influential members of his family and key associates.
US and European delegations hope to put the draft resolution to a vote in the 15-nation Security Council as soon as possible. The sanctions are the Western nations' response to Damascus' five-month crackdown on pro-democracy demonstrators, which the UN says has left 2,200 civilians dead.
But Russia, which has veto-power, said it does not think sanctioning Damascus is the right approach at the moment.
The resolution, drafted by Britain, France, Germany, Portugal and the United States and obtained by Reuters news agency on Wednesday, says the council "strongly condemns the continued grave and systematic human rights violations by the Syrian authorities" and "demands an immediate end to the violence."
While it would call for freezing Assad's financial assets, as it does for 22 other Syrians, it excludes him from the list of Syrians facing an international travel ban.