Soldiers used explosives against protesters in the central city of Hama, wounding several people as demonstrators took to the streets on Friday to call for the fall of the regime, the Syrian Observatory for Human Rights said.
"Several people were wounded when the army used explosive devices to target protesters," the Britain-based watchdog said in a statement.
Elsewhere in the province, demonstrators protested against an anti-Islamic film made in the United States that has sparked violent anti-US rallies in several Arab countries.
In Kafr Zeita, hundreds of people chanting for the fall of President Bashar al-Assad also shouted slogans denouncing the film that mocks Islam and the Prophet Mohammed.
"There is no God but God, and Mohammed is his Prophet!" cried protesters, according to amateur video posted on YouTube by activists.
Hama, a key arena of the anti-Assad uprising, suffered the worst of anti-Muslim Brotherhood repression in the 1980s, led by Assad's father and predecessor Hafez.
"Of course the film has angered many people, but what is interesting is that there was no violence from the protesters," said one Hama-based activist calling himself Abu Ghazi. "They protested in a civilised way."
In the northwestern province of Idlib, protesters in Kfar Nabal, known for their witty signs, carried a drawing of a cleric with "Muslims" written on his robe and the crescent symbol of Islam above his head.
Enraged, he points to a reel of film representing the inflammatory video, but his back is to Syria, shown as a burning mosque and a man lying in a pool of blood, completely ignored in the background.
A video from Amouda, in the northwest Hasaka province along the Turkish border, shows young protesters marching down the street waving Kurdish flags alongside the Syrian opposition flag.
Women, not generally seen at protests in violence-wracked Syria, are noticeably present, mostly unveiled and walking in long flowing skirts and jeans alongside male demonstrators.
In the city of Idlib, which is regime-controlled but located near scores of rebel-held towns and villages, scores of protesters took to the streets, according to amateur video posted on YouTube.
"We are democracy! We are