Israel fired artillery shells at two targets in Syria on Sunday evening after two Syrian mortar shells landed in Israeli territory in the past two days, the IDF said.
One mortar shell landed earlier on Sunday in an open area in the northern Golan Heights, after another round hit the same area on Saturday. They caused no damage or injuries.
The two rounds, the Israeli army said, were likely errant fire from the fighting between regime and rebel forces close to the border.
The targets of the Israeli strike were two army posts in the central Golan Heights on the Syrian side of the border, the IDF Spokesperson's Unit said in a statement.
The Israeli army said it holds the Syrian army responsible for the incident and that it "will not tolerate any attempt to breach the sovereignty of the State of Israel."
Defense Minister Moshe Ya'alon said following the Israeli attack that Israel considers the errant fire from Syria as "crossing a red line." "The State of Israel has no intention of tolerating such incidents, and therefore the IDF attacked two Syrian army cannons this evening," Ya'alon said.
"We see the Syrian regime and its military as responsible for what occurs in their territory," Ya'alon said, adding that Israel would act to prevent any attempt to harm the safety of its citizens.
Syrian President Bashar Assad's military has in recent days renewed his campaign against rebel forces near the town of Quneitra, located near the border with Israel. Last year rebel groups, including the Al-Qaida-affiliated Nusra Front took control of the area and cornered forces loyal to Assad to a bloc comprising some 10 percent of the border with Israel.