An elite Syrian army unit advanced to within quarter of a mile of the Turkish border, expanding an onslaught against opponents of President Bashar al-Assad.
Escalating an already acute refugee crisis, hundreds of Syrian civilians cut their way through a border fence into Turkey as they fled an advance into the frontier village of Khirbet al-Joz by the army's Fourth Division and Presidential Guard, led by Mr Assad's feared brother Maher.
Turkey has watched Mr Assad's brutal operation to quell opposition in Syria's restive northwest with growing alarm and has resorted to increasingly muscular diplomacy to demand an end to military operations close to the border. Most significantly,
Turkish officials last week raised the possibility of a limited military incursion into northern Syria to protect civilians.
The offensive has already seen more than 10,000 refugees flee into Turkey. .