Syrian regime bombing killed four civilians on Sunday in southern Daraa province, despite a deal brokered by Russia, regime's main foreign backer, to reduce fighting, local activists said.
The ground and aerial bombardment struck towns of Alma, al-Ghariya in the eastern countryside as well the rebel-held Old City of Daraa was hit by artillery shells.
Under an agreement that took effect at midnight on Friday, fighting was intended to subside over six months in four "de-escalation zones" where violence between the army and rebels have been most intense.
Fighting also took place in the Qaboun district of Damascus, said the Syrian Observatory for Human Rights said.
The deal was agreed during ceasefire talks in Astana in Kazakhstan between the Syrian government's backers Russia and Iran, and the main rebel sponsor Turkey.
The regime said it supported the proposal but added that it would continue to fight what it called terrorist groups around the country. Bashar Assad has said previously that all the rebel groups fighting to oust him are terrorists.
Opposition groups rejected the deal, saying that special zones threatened Syria's territorial integrity, that any role for Iran was unacceptable, and that Russia had been unable to get Assad to respect previous ceasefire agreements.
The regime army seized control of the village of al-Zalakiyat north of Hama on Sunday amid a heavy bombardment, a war monitor reported, despite a deal brokered by Russia, Syria's main foreign backer, to reduce fighting.
Violence has raged in the countryside north of Hama for over a month, since rebels there launched an assault against government forces that was quickly reversed and has now turned into an army push into areas the insurgents gained last year