Syria's military has moved into a village near the border with Turkey and another near the boundary with Lebanon, activists say.
Hundreds of Syrians, some with gunshot wounds, have fled into Lebanon, according to reports.
Disturbances were also reported as funerals were held for about 20 people estimated killed in protests on Friday.
Syrian dissidents plan a conference in the capital, Damascus, on Monday to discuss how to resolve the crisis.
The rebellion against the regime of Syrian President Bashar al-Assad has gone on for more than three months and is estimated to have left more than 1,300 protesters dead.
The village of Najia, near the border with Turkey, is the latest to have Syrian army troops and tanks move in, activists say.
Najia is near Jisr al-Shughour, the town where the government said earlier this month that 120 security personnel had been killed. Jisr al-Shughour has already been seized by the army.