AMMAN, April 12 (Reuters) – Iran has used earthquake relief flights to bring weapons and military equipment into its strategic ally Syria, nine Syrian, Iranian, Israeli and Western sources said.

The sources told Reuters that the goal was to buttress Iran’s defences against Israel in Syria and to strengthen Syrian President Bashar al-Assad. Reuters is the first to report this development.

After the Feb. 6 earthquake in northern Syria and Turkey, hundreds of flights from Iran began landing in Syria’s Aleppo, Damascus and Latakia airports bringing supplies, and this went on for seven weeks, the sources said. More than 6,000 people died in all of Syria, according to the United Nations.

The supplies included advanced communications equipment and radar batteries and spare parts required for a planned upgrade of Syria’s Iran-provided air defence system in its civil war, said the sources, two regional sources and a Western intelligence source said.

Reuters spoke to Western intelligence officials, sources close to the Iranian and Israeli leadership as well as a Syrian military defector and a serving Syrian officer about the flights for this article.

When asked if Iran had used humanitarian relief planes after the earthquakes to move military equipment to Syria to enhance its network there and help Assad, Iran’s mission to the United Nations in New York said: “That’s not true.”

Syria’s government did not respond to a request for comment.

Regional sources told Reuters that Israel quickly became aware of the flow of weapons into Syria and mounted an aggressive campaign to counter it.

Brigadier General Yossi Kuperwasser, an insider and former head of research in the Israel army as well as ex-general director of the Ministry of Strategic Affair said Israeli air strikes against the shipments relied on intelligence so specific that Israel’s military knew which truck in a long convoy to target.

‘SIGNIFICANT MOVEMENTS’

An Israeli defence official, who asked to remain anonymous, told Reuters: “Under the guise of shipments of earthquake aid to Syria, Israel has seen significant movements of military equipment from Iran, mainly transported in parts.”

He said the aid was mainly delivered to Syria’s northern Aleppo airport. Shipments were organised, he said, by the Unit 18000 Syrian division of the Quds Force, the foreign espionage and paramilitary arm of Iran’s Revolutionary Guards, led by Hassan Mehdoui.