Friday was the bloodiest day since protests began last month.
The groups, including the National Organization for Human Rights in Syria, called on the government to set up a judicial investigation committee to try those who shot at protesters and to release all political detainees.
The groups said in their Saturday statement that the highest toll was in the central city of Homs where 19 people were killed. In the southern village of Izraa, 18 were shot dead, they said.
In the past five weeks, Syrian security forces have launched a deadly crackdown on demonstrations, killing about 300 people, according to human rights groups – Yahoonews