More than 50 Syrians were killed as tens of thousands of protesters rallied for a "day of rage" after Friday prayers, defying warnings of a harsh crackdown, rights activists and officials said.
Protests against President Bashar al-Assad's regime were held in most major towns, witnesses said, in pro-democracy demonstrations after the Muslim weekly prayers as on past Fridays. At least 32 civilians were killed in the protest epicentre of Daraa, the London-based Syrian Observatory for Human Rights said, adding it had a list of names of those confirmed killed.
Military officials said four soldiers were also killed and two captured by "armed terrorists" in Daraa, though a rights activist in the southern town said the men had been killed defending protesters.
And in Homs, at least 15 civilians were killed in the industrial city, the Observatory said, updating an earlier toll from an activist.
The interior ministry said three members of the security forces were also killed in Homs.
"Three police officers... were shot dead today after being targeted by extremist terrorist groups when they performed their duties," the official SANA news agency quoted a ministry source as saying.
The Observatory said one person was also killed in the Mediterranean port city of Latakia.
In Geneva, the UN Human Rights Council endorsed a US call for an investigative mission on the bloodshed as it voted in favour of a resolution condemning the crackdown on protests.
The resolution "unequivocally condemns the use of lethal violence against peaceful protestors by the Syrian authorities... and urges the Syrian government to immediately put an end to all human rights violations".
The United States, meanwhile, blocked the assets of President Assad's powerful brother, Maher, several other officials and of Syria's intelligence services.
Ahead of Friday's bloodshed, dissidents said security forces using live rounds and tear gas already killed more than 450 people since the pro-democracy protests erupted in mid-March.
Friday's rallies come as the European Union met in Brussels to consider a wide range of sanctions against Damascus.
The call for mass demonstrations was issued on a Facebook page, The Syrian Revolution 2011, a motor of the protests in which demonstrators inspired by uprisings across the Arab world are seeking greater freedoms.
Assad's embattled regime reiterated its running ban on demonstrations, despite having lifted a decades-old law barring them earlier this month, as the Muslim Brotherhood accused it of genocide.
Information minister Adnan Mahmud told AFP the crackdown would continue, saying the "authorities are determined to restore security, stability and peace to the citizens.
The interior ministry appealed to Syrians not to join the protests and warned that unauthorised rallies would not be tolerated.
It called on "brother citizens to contribute in an effective way to stability and security... by not staging demonstrations or sit-ins for any reason without official permission," it said, quoted by SANA.
"The laws in force in Syria will be applied to preserve the security of citizens and the country's stability," it added.
Similar protests after Muslim weekly prayers on April 22 ended in chaos, with more than 100 people killed when security forces fired on demonstrators with tear gas and live rounds. Hundreds of others were detained.
In Banias, about 10,000 people turned out on Friday, shouting "liberty, solidarity with Daraa" and "down with the regime."
In Deir Ez-Zor, northeast of the capital, two demonstrators were beaten with batons and electrical cables after 1,000 people emerged from a mosque and were dispersed by security forces, rights activist Nawwaf al-Bashir said.
Some 15,000 people turned out in the majority Kurdish city of Qamishli and neighbouring towns, shouting "national unity" and "with our soul and with our blood we will sacrifice ourselves for Daraa," activists said.
And besides Homs, where thousands of people could be seen shouting "down with the regime" on videos fed to the Internet, demonstrations were also staged in Saqba and Midan, near the capital.
In Daraa itself, security forces opened fire as "thousands of people" from neighbouring towns tried to "bring aid and food" to the city, besieged by the army since Monday, an activist at the scene said.
Also in Daraa, "an armed terrorist group attacked a military post at dawn," SANA quoted a military official as saying. "Four soldiers were killed and two were captured."
Water and power have been cut in Daraa as the situation worsened after between 3,000 and 5,000 troops backed by tanks stormed the town on Monday.
Syria has been rocked since March 15 by increasingly strident anti-regime demonstrations.
In Brussels, the European Union was poised to punish the savagery in Syria with "large agreement" among member states for action against the brutal crackdown, a senior EU diplomat said.