At least 16 people were killed on Friday when security forces shot at anti-government protesters in several Syrian cities, according to activists, DPA reported.
A child was killed in Damascus where security forces fired at protesters calling for the ouster of President Bashar al-Assad, reported the opposition Syrian Media Centre.
Security forces also opened fire at pro-freedom demonstrators in Idlib near the Turkish border and other restive Syrian areas, leaving at least 15 people dead, said the Local Coordination Committees of Syria.
Footage posted by opposition activists on the internet on Friday showed mass protests in the central cities of Hama and Homs.
Syrian activists called for protests following Friday noon prayers across the strife-torn country to slam a continuing security crackdown and press for democracy.
The day was dubbed "Friday of Freedom Prisoners," in honour of those jailed during months of protests against the government of al-Assad.
Activists, quoted by al-Jazeera broadcaster, said that army troops protected on Friday protesters from security forces in the southern city of Dara.
Late Thursday, state television reported that armed groups were seen in the eastern city of Deir al-Zour. The report included footage of what it described as subversive groups who had allegedly attacked a pro-government march near Damascus.
The "armed groups" kidnapped two policemen and a high school student in the central city of Hama, according to the television report.
More than 1,400 people have been killed by security forces in the unprecedented protests since mid-March, human rights groups say.
But the government has disputed the figure and blamed "armed thugs" and foreign conspirators for the unrest.
The reports are difficult to verify because the Syrian authorities have banned most foreign media and international human rights groups from entering the country.