Israel's army said it had launched air strikes on Wednesday on Iranian and Syrian targets inside Syria, calling it a retaliatory attack after it found explosive devices along its northern border.
Lieutenant-Colonel Jonathan Conricus, an Israeli military spokesman, said eight targets were hit, belonging to the Syrian army or Iran’s Quds Force, in areas stretching from the Syrian-controlled side of the Golan Heights to the Damascus periphery.
They included an Iranian headquarters at Damascus international airport, a “secret military site” that hosted Iranian military delegations, and the 7th Division of the Syrian armed forces, he said.
The "Damascus airport headquarters" has now been identified as the so called "glass house," an Iranian military site which has been bombed on several occasions.
The recent escalation began on Tuesday, when Israel's military said it had discovered improvised explosive devices on its side of a border crossing point with Syria.
The bombs "were placed by a Syrian squad led by Iranian forces," an army statement said.
"In response, overnight, ... fighter jets struck military targets belonging to the Iranian Quds force and the Syrian Armed Forces," it said.
The Israeli statement said than in addition to striking military infrastructure, "Syrian surface-to-air missile batteries were struck."
Three Syrian soldiers were killed, according to state media, although the Syrian Observatory for Human Rights, an activist group tracking casualties in the war, claimed that 10 personnel had been killed, including five Iranians. There was no way to verify their claims.
Israel has carried out hundreds of air and missile strikes on Syria since the civil war broke out in 2011, targeting Iranian and Lebanese Hezbollah forces as well as government troops.
The Israeli Defence Ministry rarely acknowledges individual strikes, but has done so when it says it is responding to specific attacks on Israeli territory.
Images of the Iranian IEDs, tweeted by security analyst Emanuel Fabian, showed crude looking devices and it was not clear what tactical aim the Iranians had, or what message they were trying to send, by planting the bombs, given the scale of retaliation.
Israeli Defence Minister Benny Gantz, on a visit to the northern border on Tuesday, said Israel would not tolerate the planting of explosives in the Golan, territory captured from Syria in the 1967 Middle East war.
"We cannot turn a blind eye to this. It's a grave incident," Mr Gantz told reporters.
Israel has repeatedly attacked Iranian targets in Syria and those of allied militias, including Lebanon’s Hezbollah. Mr Gantz said Israel held Syria responsible for "everything that occurs on [Syrian] territory".
"What is going on at the Golan border is an exchange of messages," said Joe Truzman, an analyst with US website The Long War Journal, a website affiliated with the Foundation for Defence of Democracies which tracks terrorist violence globally.
"Israel has repeatedly stated they would act against malign activity by any Iranian-backed proxy on its borders. In early August a four-man team were caught on the Alpha Line planting explosives. All four were killed and the IDF took an additional step by bombing Syrian army bases near Damascus the following day. The message the IDF conveyed after the August event was the same as the message conveyed yesterday: We hold the Syria government responsible for all activities on its soil," he added.
The most recent campaign of Israeli air strikes in Syria began in 2013, when Hezbollah stepped up the movement of equipment into the country, including long range missiles to bolster its vast arsenal of weapons on the Lebanese border.
As President Bashar Al Assad's government floundered amid an increasingly powerful rebellion, Iran and its allies stepped up assistance to the Syrian regime, with Tehran seeing an opportunity to entrench itself in Syria and potentially, open up a new rocket front along the Syrian-Israeli border. The purpose of this second front was to complement Hezbollah's positions in southern Lebanon, which bristle with an estimated 100,000 rockets.
"Israel's concern is that its border with Syria does not turn into a Lebanon 2.0," said Mr Truzman.
"The Palestinian factions in Gaza on its southern border and Hezbollah on its northern border has kept Israel in a state of conflict for decades. They don't want a third front," he said.
As the risk of a three front war grew, the Israeli air campaign soon escalated, at times killing Iranian military advisors, members of Hezbollah and pro-Iran Iraqi militias.
According to Mr Truzman, the pattern of sporadic attacks and Israeli counterstrikes will not diminish any time soon.
"Iran and its proxies have so far not been deterred from continuing to operate in southern Syria against Israel," he said.
