State-run Syrian television says 19 police officers and members of the security forces have been killed in the southern city of Daraa.
Witnesses in Daraa earlier said there were 16 people killed there, all of them anti-government protesters. The discrepancy could not immediately be reconciled.
Daraa was the site of a mass demonstration on Friday by thousands of anti-government protesters.
Witnesses and human rights groups said security forces opened fire to disperse the gathering.
A nurse at the city's hospital said hundreds of wounded people had overwhelmed the facility.