An Israeli air strike hit near Syria’s Aleppo airport early Wednesday, causing “material damage” and shutting down operations there, Syrian officials said, while regional intelligence sources said the attack hit an Iranian arms depot.

Israel has for years carried out attacks against what it has described as Iran-linked targets in Syria, where Tehran’s influence has grown since it began supporting President Bashar al-Assad in the civil war that started in 2011.

In the third attack on Aleppo airport in six months, Israel launched “a number of missiles from the Mediterranean Sea, west of the coastal city of Latakia, at 3:55 a.m.”, the Syrian defence ministry said in a statement on state media.

The strike put the airport out of service and teams were working on repairs, Bassem Mansour, the head of Syria’s civil aviation service, told local media outlet Sham FM.

An Israeli military spokesperson declined to comment.

Two regional intelligence sources said the strike hit an underground munitions depot linked to the nearby Nairab military airport, where missile systems delivered on several Iranian military planes had been stored.

In the last year, pro-Iranian militias have expanded their influence in Syria’s northern Aleppo province, where they maintain several major bases and extensively support local paramilitary groups that operate there, the two sources added.

Nairab military airport has been used regularly for Iranian arms deliveries and the movement of troops, the intelligence sources said. They declined to be identified because of the sensitivity of the matter.

Iran has increased the use of the airport to deliver more arms during the past month, taking advantage of heavy air traffic as cargo planes offload relief aid following February’s deadly earthquake, three Western intelligence sources say.

An Israeli strike on March 7 that knocked Aleppo airport out of service blew up an Iranian arms cargo shipment hours after it was delivered by a plane that Damascus said was carrying aid, the Western intelligence sources say.

Syria has said the strikes, which have been condemned by its biggest backer, Russia, and Iran, were disrupting much-needed aid for quake victims.

Damascus denies allegations that Iran, whose top military officials frequently visit Syria and have signed deals to supply advanced weapons, has an extensive military presence in the country.

Israel has intensified strikes on Syrian airports and air bases in particular to disrupt Iran’s use of aerial supply lines to deliver arms to its allies, including Lebanon’s Iran-backed Hezbollah, which has also deployed fighters to back Assad.

Fighters allied to Iran, including Hezbollah, now hold sway in vast areas in eastern, southern, and northwestern Syria and in several suburbs around the capital.