The latest assault followed another June 17 of protests, which have grown in size and scope over the last three months, despite Assad's violent clampdown on public dissent. Activists said security forces shot dead 19 protesters on June 17.

"They came at 7 a.m. to Bdama. I counted nine tanks, 10 armored carriers, 20 jeeps and 10 buses. I saw shabbiha (pro-Assad gunmen) setting fire to two houses," said Saria Hammouda, a lawyer living in the border town in the Jisr al-Shughour region, where thousands of Syrians had fled to Turkey after the army clamped down on the area this month.

Bdama is one of the nerve centers providing food and supplies to several thousand other Syrians who have escaped the violence from frontier villages but chose to take shelter temporarily in fields on the Syrian side of the boundary.

European powers initiated a detente with Assad before the unrest to try to draw the Syrian leader away from Iran and also stabilize Lebanon.

But they now say Damascus should face tougher sanctions over the violence against demonstrators seeking more political freedoms and an end to corruption and poverty.

Syrian rights groups say at least 1,300 civilians have been killed and 10,000 people detained since March. One group has said more than 300 soldiers and police have also been killed.