Israeli aircraft bombed targets around Damascus on Wednesday night, the third round of air strikes in the past week which some analysts claim have targeted Iranian drones on the ground.
Israel did not comment on the air strikes, announced by the Syrian military, which said it had activated air defences against Israeli “aggression”, at 12.30am.
The Syrian army did not say exactly where the aircraft had struck, but Damascus airport and its environs are host to numerous air defence sites and known Iranian facilities.
Israel bombed the airport in June, destroying the runways for the first time amid allegations of Iranian arms flights transferring weapons to Syria.
Regional countries, as well as the US and Nato, have renewed focus on Iran’s production and distribution of loitering munitions — explosive drones that fly into targets, sometimes called “kamikaze drones”.
Iran has made thousands of the devices with different specifications, exporting them to regional allies such as the Houthis in Yemen, allied militias in Iraq and Syria and, more recently, Russia.
Iran-allied groups including Hezbollah — which is deeply embedded in Syria — have mounted limited drone operations against Israel, but to date no large-scale drone “swarms”, have been launched.
Last Friday, the Syrian Observatory for Human Rights, a war-monitor with a network of contacts inside Syria, said that air strikes had targeted a drone manufacturing facility run by Iran at Dimas airport near the Syrian border.
Wednesday evening’s air strikes came a day after aviation monitors tracked an Iranian Ilyushin cargo plane transiting to Damascus international airport. An Ilyushin IL-76D cargo plane operated by Pouya air, which the UN says is linked to the Pars air, landed at the airport on Wednesday.
Pars air, the UN says, is linked to the Islamic Revolutionary Guard Corps, a militant wing of Iran's armed forces.
In pictures: Iran and Israel's shadow war in Syria
Aurora Intel, a consultancy that specialises in analysing and verifying security incidents, says Israeli air strikes often closely follow Iranian flights to Damascus.
Iran established an air bridge to supply arms Syria following the onset of the uprising against President Bashar Al Assad in 2011, when the US and regional countries sent arms to rebel groups in the country.
But experts say the flights are now used to transfer arms to Iran-backed groups including Hezbollah, which aims to establish a second “missile front” against Israel, to bolster an existing missile arsenal in Lebanon.
The Israeli army did not comment on the air strikes. Israel has carried out hundreds of strikes on targets in government-controlled parts of Syria in recent years, but rarely acknowledges or discusses the operations.
Israel has acknowledged, however, that it targets bases of Iran-allied militant groups, such as Lebanon’s Hezbollah, which has sent thousands of fighters to support Mr Al Assad’s forces.
The Israeli strikes come amid a wider shadow war between Israel and Iran. The attacks on airports in Damascus and Aleppo were over fears they were being used to funnel Iranian weaponry into the country.