****CONTAINS AMATEUR VIDEO WHICH REUTERS CANNOT INDEPENDENTLY VERIFY*****<br/> <br />Syrian unrest which has spilled over into Iraq now threatens the Israeli-occupied Golan Heights on Israel's northern frontier.<br/> <br />Al Qaeda offshoot group, al Nusra Front has reportedly seized control of the border crossing into Israel from Syrian government troops.<br/> <br />But during the fight, a misfired mortar struck and wounded an Israeli soldier.<br/> <br />UN observers could be seen patrolling the Golan Heights on Wednesday as Israel returned fire, attacking two Syrian military locations.<br/> <br />These weren't the only bases where President Bashar al Assad's forces were attacked.<br/> <br />In Tabqa, to the east, fighters from Islamic State claimed they had taken over another installation.<br/> <br />The militants posed on top of jets and showed off weapons and ammunition they say they seized from the army.<br/> <br />The also reportedly executed their Syrian army prisoners.<br/> <br />Tabqa has been the army's last foothold in
