Syria has entered a state of civil war with more than 4,000 people dead and an increasing number of soldiers defecting from the army to fight President Bashar Assad's regime, the UN's top human rights official has said.
Civil war has been the worst-case scenario in Syria since the revolt against Mr Assad began eight months ago.
Damascus has a web of allegiances that extends to Lebanon's powerful Hezbollah movement and Iran's Shiite theocracy, raising fears of a regional conflagration.
The assessment that the bloodshed in Syria has crossed into civil war came from the UN High Commissioner for Human Rights, Navi Pillay.
The conflict has shown little sign of letting up. Activists reported up to 22 people killed on Thursday, adding to what has become a daily grind of violence.
"We are placing the (death toll) figure at 4,000 but really the reliable information coming to us is that it's much more than that," Ms Pillay said in Geneva.
"As soon as there were more and more defectors threatening to take up arms, I said this in August before the Security Council, that there's going to be a civil war," she added. "And at the moment, that's how I am characterising this."
US State Department spokesman Mark Toner declined to call it a civil war. "The overwhelming use of force has been taken by Assad and his regime," Mr Toner told reporters. "So there's no kind of equanimity here."
Mr Toner said Mr Assad's government has taken Syria down a dangerous path, and that "the regime's bloody repression of the protests has not surprisingly led to this kind of reaction that we've seen with the Free Syrian Army".
The Free Syrian Army, a group of defectors from the military, has emerged as the most visible armed challenge to Mr Assad. The group holds no territory, appears largely disorganised and is up against a fiercely loyal and cohesive military.
