BEIRUT (AP) -- Iran and Russia joined the Lebanese militant group Hezbollah in condemning a rare Israeli airstrike on Syria, enflaming regional tensions already heightened by the civil war against President Bashar Assad.
Israel launched the airstrike inside Syria on Wednesday, U.S. officials said, targeting a convoy believed to contain anti-aircraft weapons bound for Hezbollah, an archenemy of Israel.
However the Syrian military denied the existence of any such weapons shipment and said a scientific research facility outside Damascus was hit by the Israeli warplanes. It said the target was in the area of Jamraya, northwest of Damascus and about 15 kilometers (10 miles) from the Lebanon border.
Russia, Syria's strongest international ally, said Moscow is taking "urgent measures to clarify the situation in all its details."
"If this information is confirmed, we have a case of unprovoked attacks on targets in the territory of a sovereign state, which grossly violates the U.N. Charter and is unacceptable," Russia's foreign ministry said in a statement. "Whatever the motives, this is not justified."
Iran's Foreign Minister Ali Akbar Salehi condemned the airstrike on state television, calling it a clear violation of Syria's sovereignty.
Hezbollah, closely allied with Syria and Iran, said it "expresses full solidarity with Syria's command, army and people."
Hezbollah did not mention any convoy in the statement but said the strike aimed to prevent Arab and Muslim forces from developing their military capabilities.
Maj. Gen. Abdul-Aziz Jassem al-Shallal, who became in December one of the most senior Syrian army officers to defect, told The Associated Press by telephone from Turkey that the targeted site is a "major and well-known" center to develop weapons known as the Scientific Research Center.
Al-Shallal, who until his defection was the commander of the Military Police, said no chemical or unconventional weapons are at the site. He added that foreign experts, including Russians and Iranians, are usually at such centers.
Regional security officials said Wednesday the shipment included sophisticated Russian-made SA-17 anti-aircraft missiles, which if acquired by Hezbollah would enable the militants to shoot down Israeli jets, helicopters and surveillance drones. The officials spoke on condition of anonymity because they were not authorized to brief the media.
In Israel, lawmaker Tzachi Hanegbi who is close to hard-line Prime Minister Benjamin Netanyahu stopped short of confirming Israel's involvement in the strike.
But he hinted that Israel could carry out similar missions in the future. He said pinpoint strikes are not enough to counter the threat of Hezbollah obtaining sophisticated weaponry from Syria.
"Israel's preference would be if a Western entity would control these weapons systems," Hanegbi said. "But because it appears the world is not prepared to do what was done in Libya or other places, then Israel finds itself like it has many times in the past facing a dilemma that only it knows how to respond to," he added.
He was referring to NATO's 2011 military intervention in Libya that helped oust dictator Moammar Gadhafi.
"Even if there are reports about pinpoint operations, these are not significant solutions to the threat itself because we are talking about very substantial capabilities that could reach Hezbollah," he added.
Syria's civil war has sapped President Bashar Assad's power and threatens to deprive Hezbollah of a key supporter, in addition to its land corridor to Iran. The two countries provide Hezbollah with the bulk of its funding and arms.
Earlier this week, Netanyahu warned of the dangers of Syria's "deadly weapons," saying the country is "increasingly coming apart."
The same day, Israel moved a battery of its new "Iron Dome" rocket defense system to the northern city of Haifa, which was battered by Hezbollah rocket fire in the 2006 war. The Israeli army called that move "routine."
The Israeli army won't say whether Iron Dome was sent north in connection to this operation. It does note that it has deployed the system in the north before.
Syria and its allies, including Hezbollah, deny there is an uprising against the government and say what is happening is part of a conspiracy against Damascus because of its support for anti-Israeli groups.
Hezbollah said the attack is part of that conspiracy "that aims to destroy Syria, its army and vital role in the line of resistance" against Israel.
Associated Press writer Ian Deitch contributed to this report from Jerusalem.