At least four Syrian soldiers were killed and six others were wounded in an Israeli missile assault on alleged Iranian military sites around Damascus in the early hours of Monday.
The strikes are not the largest on Iranian-backed forces in Syria nor are they the deadliest. But Israeli political and military leaders have been far more overt about their actions in Syria as evidenced by Monday's attack which Israel reported in real time.
By announcing both the strikes and their targets, Israeli officials departed from their years-long policy of ambiguity regarding activities in neighbouring Syria.
Prime Minister Benjamin Netanyahu said Israel's air strikes mainly targeted military positions set up by Iran, which he warned would face consequences for threatening to destroy Israel.
"We are operating both against Iran and against the Syrian forces that are abetting the Iranian aggression," he said in a speech. "We will strike at anyone who tried to harm us. Whoever threatens to eliminate us, bears full responsibility."
Meanwhile, the head of Iran's air force said his pilots were ready to respond.
"The young people in the air force are fully ready and impatient to confront the Zionist regime and eliminate it from the Earth," Brig Gen Aziz Nasirzadeh was quoted as saying by the Young Journalist Club, a website supervised by state television.
Monday's strikes were the second Israeli attack in less than 24 hours. An earlier assault struck the southern outskirts of Damascus on Sunday. The latest incident is also the third rocket attack by Israel on Syria this month.
The scale and intensity of the overnight strikes suggest a serious escalation between Israel on one hand, and the Syrian government and Iran on the other.
It raises the risk of open confrontation at a time when Israel is concerned about Iranian expansion in Syria after a decision by US President Donald Trump to withdraw American forces from the country.
It also comes ahead of April 9 elections in Israel and coincides with the US vowing more action on Iran.
"The Israeli attacks on Iranian assets in Syria is part of the larger process of breaking Iran's logistics chain to its supporters especially Hezbollah," Theodore Karasik, a senior adviser at the Gulf State Analytics think tank told The National. "These strikes fit in neatly with US and allied goals in Syria."
Israel's armed forces said the strikes targeted a munition storage area, an Iranian military zone at Damascus International Airport, Iranian intelligence headquarters and an Iranian training camp.
The army also said it fired on Syrian air defences after they launched surface-to-air missiles in an attempt to intercept the Israeli misiles.
The attack, the Israeli military said, was in response to Iranian forces in Syria launching a surface-to-surface rocket towards the northern Golan Heights on Sunday. The Israeli army said it had intercepted that attack.
“By firing towards Israeli civilians, Iran once again proved that it is attempting to entrench itself in Syria, endangering the state of Israel and regional stability,” the Israeli army tweeted.
“We hold the Syrian regime responsible for everything taking place within Syria and warn them against targeting Israel or permitting others to target Israel from their soil.”
The Israeli military said it is “prepared for all scenarios and will continue operating as needed to defend Israeli civilians”.
Lt Col Jonathan Conricus, an Israeli military spokesman, said the Iranian missile attack that prompted the strong Israeli response was "premeditated". Iranian forces in Syria fired the mid-range missile toward Israel from the Damascus area - a missile that had been smuggled into Syria specifically for that purpose, he said.
Mr Conricus said the missile hadn't been used in any of the internal fighting of the civil war and had "no business" being in Syria.
"We saw that as an unacceptable attack by the Iranian troops -- not proxies, not Shiite militias, not Syrian forces -- Iranian troops firing an Iranian-made missile from the vicinity of Damascus towards sovereign Israel," Mr Conricus told journalists.
Russia's National Defence Control Centre said that Syrian air defences destroyed more than 30 cruise missiles and guided bombs launched by Israel on Monday.
It said infrastructure at the capital's airport was damaged, adding that four Syrian troops were killed and six others were wounded.
The Syrian Observatory for Human Rights said 11 people had been killed.
It said air strikes and ground-to-ground missiles hit targets around the capital including near the Damascus airport, as well as near the Thaala military airport in Sweida province to the south of the capital.
The targets included weapons depots belonging to the Lebanese Shiite movement Hezbollah and Iranian fighters, it added.
Syrian state media, citing a military source, said the country had endured "intense attack through consecutive waves of guided missiles, but had destroyed most 'hostile targets'".