Syrian troops massed near the Turkish border overnight as President Bashar al-Assad uses increasing military force to crush protests against his rule.
Eyewitnesses said hundreds of displaced Syrians fled into Turkey as tanks approached the makeshift camps where they had been sheltering on the Syrian side of the border.
Some 10,000 Syrians have already fled into Turkey to escape the military crackdown. The opposition estimates 1,400 people have been killed since widespread protests against Assad's rule began three months ago.
The crackdown has drawn international condemnation, while the United States and the European Union have imposed sanctions on Assad and his top aides.
compiled from agency reports