JERUSALEM (Reuters) - Israel threatened on Sunday to respond should stray Syrian ordnance continue to strike the Israeli-occupied Golan Heights, highlighting international concerns that the civil war in Syria could ignite a wider regional conflict. The remarks by Defense Minister Ehud Barak came days after Israel told Syrian President Bashar al-Assad to rein in attacks on rebels near the Golan, a strategic plateau that Damascus lost to the Jewish state in the 1967 Middle East war and which had been mostly quiet for decades. "The message has certainly been relayed. ...