Iran smuggled weapons and military equipment into Syria using humanitarian aid shipments as a cover following a devastating earthquake there in February, two sources familiar with US intelligence and an Israeli defense official told CNN.
The intelligence suggests that Iran's Islamic Revolutionary Guard Corps., and specifically the IRGC's Quds Force which specializes in unconventional warfare, used convoys from Iraq to covertly transport the arms and ammunition into Syria, the source said.
Intelligence officials believe the weapons were destined for Iranian proxy groups in Syria, who have repeatedly attacked US military personnel stationed there as part of the anti-ISIS coalition.
"The humanitarian assistance of Iran to Syria was used as an umbrella of moving weapons capabilities into the region," the Israeli defense official said.
The Washington Post reported on the weapons shipments on Sunday, citing a leaked US intelligence document -- part of a trove allegedly leaked online over the last year by Massachusetts Air National Guardsman Jack Teixeira. Reuters earlier reported that regional and western officials believed Iran was smuggling the weapons under the guise of earthquake relief.
President Joe Biden has ordered several airstrikes against Iran-backed militia groups in Syria, including as recently as March, when an American contractor was killed and five US service members were injured after a suspected Iranian drone targeted a coalition military base.
Foreign aid poured into Syria and Turkey after February's earthquake, which killed more than 50,000 people. The magnitude 7.8 quake was one of the strongest to strike the area in more than a century, with Turkey's Disaster and Emergency Management Agency (AFAD) calling for international help.
The US has bolstered its military forces in the Middle East following a series of attacks on US troops in Syria attributed to Iranian-affiliated militias, the Pentagon said in March. The US responded with precision air strikes on facilities associated with Iran's Islamic Revolutionary Guards Corps.
A squadron of A-10 attack aircraft deployed to the region ahead of a scheduled deployment, several weeks earlier than scheduled following the attacks in Syria. In addition, the US ordered a carrier strike group to remain in the region to support US forces in Central Command, which covers the Middle East, and a squadron of A-10 attack aircraft to the region.
The US has approximately 900 troops in Syria as part of the ongoing mission to defeat ISIS. But those forces, spread across several bases in northeast Syria, have become a frequent target for Iran and its proxies in the region, who can launch drone or rocket attacks against US positions.
"Iran threatens to push the Middle East into regional instability by supporting terrorist and proxy forces," Joint Chiefs Chair Gen. Mark Milley told lawmakers in March.
In recent weeks, airstrikes said to be from Israel targeting Iranian-linked groups in Syria have intensified. An attack in late March attributed to Israel killed two military advisers with the Islamic Revolutionary Guard Corps.
Israeli officials rarely directly confirm Israel's role in such strikes, but last month, Israeli Defense Minister Yoav Gallant told Israeli reporters that in the first quarter of 2023, "we doubled the rate of attacks in Syria." Gallant's spokesperson confirmed the remarks to CNN.
Speaking in Greece last week, Gallant also said that "Over the past six months, Iran has sent aircraft to Syria on a weekly basis, delivering weapons to be used for terrorism. The Syrian regime should be aware that the IDF will respond forcefully to any attacks launched from its territory."
He added: "We will not allow Iran to establish military power in Syria, or to build a highway for the delivery of advanced weapons to Lebanon"