Israel forces strike Syria army position after fresh stray fire
An Israeli military spokeswoman said a mortar round had hit open ground in the Israeli-controlled zone of the plateau and "forces responded and targeted the Syrian army position that fired the mortar."
She did not say if the Israeli retaliatory fire had come from ground or air forces.
Prime Minister Binyamin Netanyahu had been visiting the Israeli settlement of Katzrin, further south in the Golan, at the time of the exchange of fire.
"During my speech, shells from the Syrian side landed in our territory and the Israel Defence Forces have already struck back," the Israeli premier said in an English-language statement.
"I said that we will not tolerate spillover and that we will respond to every firing," he said.
"Whoever attacks us - we will attack him. This is our policy and we will continue with it."
On Sunday Israel hit "two artillery positions and an ammunitions truck belonging to the Syrian regime," and the army ordered Israelis to keep away from open areas near the ceasefire line.
The day before, Israeli aircraft hit two Syrian army tanks and what Israel said was a machinegun position, after 10 projectiles from Syrian internal conflict fell in the Israeli-held zone.
Israel has conducted several airstrikes in Syria since that country's civil war erupted in 2011, most of which it has said had been against arms convoys or warehouses of its Lebanese arch-foe Hizballah - a key supporter of the Syrian regime.
In April, Israel shot down what it identified only as "a target" over the Golan, hours after Syria accused it of hitting a military position near Damascus airport. Israel did not confirm or deny the reported Damascus attack.
Israel seized 1,200 square kilometres (460 square miles) of the Golan Heights from Syria in the Six-Day War of 1967 and later annexed it in a move never recognised by the international community.
Meanwhile, around 510 square kilometres of the Golan are under Syrian control.
The Israeli side of the Golan has been hit sporadically by what is thought to be stray fire from fighting between forces loyal to Syria's government and rebels.
Syria and Israel are still technically at war.