Israeli fighter jets, attack helicopters and other warplanes have struck military targets in southern Syria, a day after thwarting an attack in the Golan Heights, the Israeli army said.
"The targets struck include observation posts and intelligence collection systems, anti-aircraft artillery facilities and command and control systems in SAF (Syrian Armed Forces) bases," the army said in statement.
Syrian state media said Syria had activated its air defences against "hostile targets" near the capital Damascus.
It also said Israeli helicopters fired at Syrian checkpoints in al-Qunaitra, on the Golan Heights, causing material losses. There was no immediate word of any casualties.
The Israeli army said earlier it had killed four men laying explosives late Sunday near the Israeli-occupied sector of the Golan Heights, the latest security incident on the tense northern borders.
The Israel Defence Forces confirmed the incident prompted the air strikes.
"In response, a short while ago, IDF fighter jets, attack helicopters and aircraft struck military targets in southern Syria, belonging to the Syrian Armed Forces," the IDF said in a statement.
"The IDF holds the Syrian government responsible for all activities on Syrian soil, and will continue operating with determination against any violation of Israeli sovereignty," it said.
Tensions are already high between bitter rivals Israel and Syria since a fighter with the Iranian-backed Lebanese movement Hezbollah was killed in an apparent Israeli air strike in Syria two weeks ago.
Last month, Israeli army helicopters struck military targets in southern Syria in retaliation for earlier "munitions" fire towards Israel.
Israel did not directly blame Syrian forces for the munitions fire, but said it held the Damascus government responsible.