Rebels seized a border crossing on the demilitarized zone between Israel an Syria on Thursday, activists said, as heavy clashes raged between the opposition and President Bashar al-Assad's forces.
The Britain-based Syrian Observatory for Human Rights said it was the first time that rebels had seized a border crossing next to the Israeli occupied Golan Heights, but it was unclear whether the anti-Assad fighters would be able to hold the site.
Israel is worried that the Golan, which it captured from Syria in 1967, will become a springboard for attacks on Israelis by jihadi fighters, who are taking part in the armed struggle against Assad.
"The rebels have seized the crossing near the old city of Quneitra in the occupied Golan Heights," said Rami Abdelrahman, head of the Observatory. "There are heavy explosions and fierce clashing ongoing in the area."