Israel has been dragged closer to the Syrian civil war after using tanks to attack Syrian mobile artillery which had earlier fired a round harmlessly into the Golan Heights.
The escalation of the border tensions between Syria and Israel, which occupied the Syrian Golan in 1967, came as Israel's leadership continued to wrestle with what to do about violence from the Gaza Strip.
The Israeli army said that it used its Merkava tanks to strike at "mobile artillery" which had been spotted firing into Israeli territory.
The direct hit came a day after Israel fired a Tammuz camera-guided anti-tank missile close to a mortar crew which had also fired into the territory it guards.
Rebels in the area then accused Israel of taking sides with Damascus.
That allegation has been, literally, blown away by the use of tanks against Syrian government heavy weapons.
The regime of Bashar al Assad might see some benefit to destabilizing Syria's neighbours.
But Israeli military sources told Sky News: "(The) last thing we need now is another front line opening up."
Meanwhile, Syria's rebel exiles have agreed to come together under the leadership of reformist cleric Mouaz al Khatib.