Up to 23 people are now thought to have been killed after security forces reportedly opened fire on thousands of anti-government protesters in the southern city of Deraa.
State-run television has said 19 police officers had been killed by armed forces in the city.
On a day of widespread protests against the 11-year-rule of President Bashar al-Assad, there were also unconfirmed reports of deaths in Homs, Duma and Harasta.
The state news agency SANA reported shooting in Deraa, but it claimed ‘vandals’ had opened fire on mass gatherings, killing a policeman and an ambulance driver and wounding dozens of police and residents.
Protesters set fire to a Baath Party outpost and smashed a stone statue of Basil al-Assad, President Assad's late brother.
Popular demonstrations calling for greater freedoms have shaken the country which has been ruled under emergency law since President Assad's Baath Party took power in a 1963 coup.
Mr Assad has responded with a blend of force against protesters, gestures towards political reform and concessions to conservative Muslims including closing Syria's only casino.
A key demand of the protesters is to repeal emergency law. Mr Assad ordered a committee to study replacing it with anti-terrorism legislation, but critics say it will probably grant the state much of the same powers.
Under President Assad, who inherited power in 2000 when his father Hafez al-Assad died after 30 years in power, Syria has been Iran's closest Arab ally, a major player in Lebanon and a supporter of militant groups Hamas and Hezbollah.
