Syrian forces shot dead three demonstrators on Friday, as tens of thousands marched across the country heeding calls by the opposition to take advantage of a hard-won UN-backed ceasefire.
Security forces opened fire at a group of men as they joined a demonstration in Assi square, killing one, the Syrian Observatory for Human Rights said.
Another demonstrator was shot dead in the village of Nawa, in the southern province of Daraa, as he walked out of a mosque to join a demonstration, the Observatory said.
Forces loyal to President Bashar al-Assad also shot dead a man in the town of Salqin, in the northwestern province of Idlib, the centre added.
The head of the Britain-based watchdog, Rami Abdel Rahman, said tens of thousands demonstrated in several provinces, a day after a UN-backed ceasefire entered into force.