Israel's military says it targeted "dozens" of Iranian military sites in Syria with missile strikes after the Golan Heights were struck with about 20 rockets in an attack it said was ordered by the head of Iran's Revolutionary Guards.
Israeli military spokesman Lieutenant General Jonathan Conricus told reporters in Jerusalem early on May 10 that Israel's army targeted sites used by Iranian intelligence, logistics, storage, and vehicles, as well as the suspected site where the missiles aimed at Israel were launched.
Conricus claimed that the commander of Iran's Islamic Revolutionary Guards Corps, Qassem Soleimani, ordered the missile attacks on the Golan Heights, which he said caused no serious damage or casualties in Israel.
"It was ordered and commanded by Qassem Soleimani, and it has not achieved its purpose," he said.
"The Israeli army takes very seriously this Iranian attack against Israel," Conricus said. "We have retaliated" by striking "dozens of Iranian military targets in Syria," he said.
He said it was one of the largest Israeli military operations in recent years and the biggest ever against Iranian targets. He said, however, that Israel is not seeking an escalation of tensions with Iran.
Israel captured the Golan Heights from Syria in the 1967 war and annexed it in 1981, although the annexation was not internationally recognized.
Israeli Defense Minister Avigdor Lieberman said on May 10 that Israel responded fiercely to what he termed an unprecedented rocket attack by Iranian forces in Syria against Israel.
He said no one was harmed in Israel and all the rockets were either intercepted or fell short.
In a statement, the Russian Defense Ministry said that 28 Israeli F-15 and F-16 fighter jets launched about 60 air-to-surface missiles during the two-hour raid early on May 10. The ministry said Israel also fired over 10 tactical surface-to-surface missiles.
Russia is a key ally of Syrian President Bashar Assad, and has been waging its own air campaign on his behalf since 2015.
The British-based Syrian Observatory for Human Rights said the Israeli strikes killed 23 fighters, including five Syrian soldiers.
The monitor said Israel struck several military posts for Syrian troops and Iranian-backed militias near the capital, Damascus, in central Syria and in southern Syria.
The White House condemned Iran for the rocket attack on the Golan Heights, adding it "strongly supports" Israel's right to self-defense.
Russia urged all side to deescalate tensions. "This is all very alarming, it causes concern," Russian news agency TASS quoted Deputy Foreign Minister Mikhail Bogdanov as saying. "There should be work to de-escalate the tensions."
That call was echoed by French President Emmanuel Macron as well as by German Chancellor Angela Merkel, who called the latest escalation a matter of "war and peace."
UN Secretary General Antonio Guterres expressed "utmost concern" over reports of Iran's rocket attack and of Israel's retaliatory strikes.
"The secretary general urges for an immediate halt to all hostile acts and any provocative actions to avoid a new conflagration in the region already embroiled in terrible conflicts with immense suffering of civilians," Guterres' spokesman said in a statement.
The exchange of fire comes one day after Syria accused Israel of launching missile strikes targeting an Iranian military outpost in Kisweh, south of Damascus.
It also comes after U.S. President Donald Trump announced on May 8 that Washington was withdrawing from a landmark nuclear agreement between six world powers and Iran under which Tehran pledged to curb its nuclear program in exchange for sanctions relief.
According to the observatory, 15 people were killed by the strikes on May 9, among them eight Iranian fighters.
Last month, an attack on Syria's T4 air base in Homs Province killed seven Iranian military personnel, and Israel was accused of striking government outposts in northern Syria, killing more than a dozen pro-government fighters, many of them Iranians.
Israel has neither confirmed nor denied most of the air strikes. But for months, it has repeatedly said it will not accept a permanent Iranian military presence in Syria.
Iran has vowed to take revenge for the strikes attributed to Israel, which have killed not only many Iranian troops but members of Lebanon's Hizballah militia, which is also stationed in Syria to support President Bashar al-Assad in his seven-year civil war against Sunni rebels.
Iranian President Hassan Rohani in a phone call with Merkel said his country does not want "new tensions" in the Middle East.
"Iran has always sought to reduce tensions in the region, trying to strengthen security and stability," he said, according to the Iranian presidency’s office. He did not mention the Israeli retaliatory strikes.
Israel has been on heightened alert in recent days, putting its forces along the northern border on high combat alert, activating air defenses, and ordering the unsealing of bomb shelters in anticipation of possible Iranian retaliation against the strikes.
The Israeli military said the measures were needed because of what it described as "unusual movements" of Iranian forces in Syria.
With the combined forces of Hizballah, Iran, Russia, and Syria making significant gains in the fighting this year, Israeli officials have said they fear that Iran and tens of thousands of allied Shi'ite militiamen will start carrying out attacks against Israel.
"They want to build a second Hizballah-stan" in Syria, Amos Gilead, a retired senior Israeli defense official, told a security conference in the coastal town of Herzliya recently. "They are determined to do it and we are determined to prevent it. It means we are on a collision course."
While periodically staging raids on Syrian and Iranian positions, Israel's military has maintained close communications with the Russian military stationed in Syria to back Assad, and has avoided striking any Russian installations.
Israeli Prime Minister Benjamin Netanyahu traveled to Moscow on May 9 to meet with President Vladimir Putin and discuss military coordination in Syria.
After visiting with Putin for 10 hours, Netanyahu said he conveyed what he described as Israel's obligation to defend itself against Iranian aggression in Syria. The Israeli military said Russia was informed of Israel's strikes against Iranian targets ahead of time.
"I think that matters were presented in a direct and forthright manner, and this is important. These matters are very important to Israel's security at all times and especially at this time," Netanyahu said.
"[Iranians] are trying to transfer forces and deadly weapons [to Syria] with the explicit goal of attacking the state of Israel as part of their strategy to destroy the state of Israel," he said.
Netanyahu said his meetings with Putin "are always important and this one is especially so.... In light of what is currently happening in Syria, it is necessary to ensure the continued coordination" between the two militaries.