Ammar Qurabi, who heads Syria's National Organization for Human Rights, said most of the deaths happened in Daraa, a restive southern city that has become a flashpoint for anti-government protests. Sixteen people were killed in Daraa, among them medical personnel as ambulances were shot at or prevented from accessing the injured, witnesses said.
One witness who helped ferry the dead and wounded to the city's hospital said he was among thousands of people at the protest and he witnessed security forces shooting live ammunition.
"My clothes are soaked with blood," he said by telephone from Daraa.
A nurse at the hospital said they had run out of beds, and that many people were being treated on the floor or in nearby mosques.
The government acknowledged violence in Daraa on Friday, but said only two people died and blamed armed thugs.
Three protesters were killed in the Damascus suburb of Harasta, and one in the central city of Homs, Mr. Qurabi said.
A cycle of insufficient concessions and continued use of violence has led to unprecedented unrest, rattling the regime of President Bashar al-Assad, whose family has ruled Syria for nearly 40 years.
A witness in Harasta near Damascus said a peaceful protest had been clamped down on by security who beat protesters before shots were fired.
Another protest in the northwestern city of Banias started with demonstrators holding olive branches and calling for freedom, but calls rose for the toppling of the regime after news of the deaths in Deraa emerged, activists said.
Meanwhile, Douma, the northern suburb of Damascus where at least 15 people were shot dead last week, saw thousands take to the streets calling for freedom but there were not any immediate reports of violence.
Kurdish communities also turned out in the north-eastern towns of Qamischli, Amouda and Derbasiyyeh less than 24 hours after Mr. Assad pledged to give nationality to 200,000 Kurds, fulfilling a decades-old demand of the country's long-ostracized minority.
Despite the overture, Kurdish sources said the community remained committed to calling for the end of emergency law, a law enabling new political parties, the release of Kurdish political prisoners and increased cultural and political rights.
