Israel strikes Syria at Golan frontier
An Israeli air strike targeted a hill in Khan Arnabeh village in Quneitra province without causing casualties, a commander in the pro-Damascus regional alliance told Reuters.
The Israeli army said it launched strikes after Syrian mortar fire struck near Israel's security fence, "part of the internal fighting between the regime and the rebels in Syria", it said, without giving details on the retaliation.
The Israel army was "not involved in the internal fighting in Syria" but "it will continue to implement the 1974 Separation of Forces Agreement that includes maintaining the buffer zone", the military added in a statement.
Syria and Israel have never signed a formal peace treaty.
Israel seized 1,200 square kilometres (460 square miles) of the Golan Heights from Syria in the 1967 Six-Day War and later annexed it, in a move never recognised by the international community.
Explainer: Golan Heights - What 's the big deal?
Israel warned on Thursday it would attack Syrian regime forces if they deploy in a demilitarised zone while advancing against opposition rebels in the south, including Daraa and Quneitra.
"We must verify and do everything to clarify, vis-a-vis the Russians, the Assad government, that we will not accept any armed presence by the Assad regime in the areas which are meant to be demilitarized," Gilad Erdan, a minister in Netanyahu's security cabinet, told the Israeli news site Ynet.
The Israeli minister cited previous examples of Israeli airstrikes carried out against Syrian facilities deemed to have been used in attacks on Israel by Iranian forces in Syria.
"Here, too, if there is a violation, and certainly in the southern Syrian region which is close to the citizens of the State of Israel, and a bringing of weaponry that should not be there, Israel will take action," Erdan said.
Earlier this week, Israel said it would not allow Syrians fleeing southern Syria to find refuge in territories under its control.