Israeli troops fired warning shots into Syria Sunday, the army said in a statement, in what public radio said was the first Israeli fire directed at the military in the Golan Heights area since the 1973 war.
"A short while ago, a mortar shell hit an IDF post in the Golan Heights adjacent to the Israel-Syria border, as part of the internal conflict inside Syria. In response, IDF soldiers fired warning shots towards Syrian areas," the army said in a statement.
Military sources told AFP that the army used a single Tamuz anti-tank missile, a weapon known for being highly accurate.
In addition, the army said in its statement it had filed a complaint through the local UN forces, warning that "fire emanating from Syria into Israel will not be tolerated and shall be responded to with severity."
Earlier on Sunday, Prime Minister Benjamin Netanyahu said Israel was "closely monitoring what is happening on our border with Syria and there too we are ready for any development."
Sunday's cross-border fire was the latest in a string of incidents in which fire has spilled from Syria across the ceasefire line.
On Thursday, three stray mortar rounds from Syria hit the Golan, which Israel seized from Syria in the 1967 Middle East war and annexed in 1981 in a move never recognised by the international community.
And on Monday, an Israeli military vehicle patrolling the buffer zone was hit by gunfire, with the army acknowledging it was caused by "stray bullets."
No one was wounded, but the incident prompted an Israeli complaint to the United Nations Security Council in which it described the gunfire as a "grave violation" of a 1974 agreement on security in the buffer zone.
Two days earlier, three Syrian tanks entered Bir Ajam village, five kilometres (three miles) southeast of Quneitra, in the demilitarised zone, sparking another Israeli complaint to the UN.
Since Israel and Syria signed the 1974 disengagement agreement, a 1,200-strong unarmed UN force has patrolled the buffer zone.