Israel attacked dozens of Iranian targets in Syria in what the military said was the most extensive strike in the neighboring country in decades. The strike was carried out in response to a barrage of 20 rockets that were fired from Syria at Israeli military outposts.

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The Israeli military accused the Revolutionary Guards' Al Quds force and its commander, Maj. Gen. Qassem Soleimani, of launching the attack at the Israeli Golan Heights. This is the first time Israel has directly accused Iran of firing toward Israeli territory.

Iran targets Israel from Syria, Israel responds

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Four of the rockets were intercepted by Israel's Iron Dome air defense system and the rest of the rockets exploded on Syrian territory, the military said. Israel said there were no casualties in the attack.

Israel said its targets included weapons storage, logistics sites and intelligence centers used by elite Iranian forces in Syria. It also said it destroyed five Syrian air-defense batteries after coming under heavy fire. It said none of its warplanes were hit.

Twenty-three fighters, among them 18 foreigners, were killed in the attack, according to the Syrian Observatory for Human Rights. The Syrian military said that three people were killed and two were wounded in the attack.

Russia's Defense Ministry said that the Israeli strike on Syria used 28 planes, fired 70 missiles, adding that Syria shot down more than half of Israeli missiles.

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Open gallery view Map of targets of Israeli strike in Syria

Defense Minister Avigdor Lieberman said Thursday morning that Israel has struck "all of the Iranian infrastructure in Syria." Lieberman said that Israel does not seek escalation, but added that it won't allow Iran to turn Syria into a "forward base" against Israel.

A source in the Israeli security establishment said this attack was the largest carried out by Israel since it signed a disengagement agreement with Syria in May 1974. The Israeli military warned Syria not to respond to its attack.

Russia is reported to have been informed in advance of the Israeli attack.

There was no immediate word on Iranian casualties. Reports said that there were several casualties as a result of the Israeli strike and that explosions were heard near the Syrian capital of Damascus.

Reports in Syria said that Israel has also struck army posts as position used by Hezbollah and Iranian-backed militias in the Syrian Golan, near the Druze village Khader and Khan Arnabah, close to the border with Israel. The reports said that the rockets that struck Israel overnight were fired from those posts.

Tensions along the Israel-Syria border

The rocket barrage was fired from Syria at Israel at around midnight Thursday. The Syrian Observatory for Human Rights reported that Israel has attacked targets of the Syrian military on the outskirts of Quneitra in the Golan Heights.

Shortly thereafter siren alerts sounded in communities in the north and center of the Golan Heights in northern Israel. The Home Front Command released a reminder on safety regulations to residents of the area; some reported hearing explosions.

The Golan Regional Council released a statement saying that several towns in the Golan were targeted by rocket fire and that residents of those towns are requested to stay in shelters until notified otherwise.

Open gallery view The rocket launcher from the Israeli air force's perspective, moments before the rockets were launched, May 10, 2018 Credit: IDF Spokesperson

Over the past month, tensions have been high along the Israeli border with Syria and the army has increased security measures in the area, deploying more Iron Dome batteries across the northern region.

On Wednesday, the Syrian Observatory said eight Iranians were among 15 killed in a strike carried out a day earlier by Israel. The strike reportedy targeted Iranian missiles aimed at Israel.

The Israeli military had anticipated that after U.S. President Donald Trump announced that he was withdrawing from the Iranian nuclear accord, Israel was likely to be targeted by rocket fire and Iran would try to retaliate for an attack last month on the Syrian T4 air base in which seven Iranians were killed. However, the military has predicted that such an Iranian retaliation would not lead to a full-fledged war.

This is the first time Israel directly accuses Iran of firing towards Israeli territory. During the Syrian Civil War, rockets were fired at Israel from Syria several times, usually by groups in southern Syria that are affiliated with Iran, Hezbollah and the Assad regime.

Tehran has issued several threats over the past month, saying that it would hurt Israel in response to a slew of attacks that were ascribed to the Israeli air force.

A U.S. State Department official responded to the escalation on Wednesday, telling Haaretz that U.S. wishes to reiterate Secretary of State Mike Pompeo's statement from last week in which he stressed the U.S. support of Israel against the Iranian threat.

"We stand with Israel in the fight against Iran’s malign activities and we strongly support Israel’s sovereign right to defend itself. If true [evidence provided by Prime Minister Benjamin Netanyahu regarding Iran's nuclear activity in recent years], this only bolsters our decision to terminate the JCPOA. Iran will have showed the world its true intentions. Let there be no doubt."

French President Emmanuel Macron called for a deescalation of tensions in the Middle East on Thursday. "The president has been kept regularly updated. He calls for a de-escalation in the situation," Macron's office said in a statement.

This attack comes on the heels of a Syrian report Tuesday accusing Israel of carrying out an attack on a military base south of Damascus, which was used by Iranian forces. According to reports, Israeli fighter jets entered Syrian airspace and struck Iranian missiles aimed at Israel.

Reuters and the Associated Press contributed to this report.