During more than 12 years of civil war in Syria, Israel has launched hundreds of air strikes on its territory, primarily targeting Iran-backed forces and Lebanese Hezbollah fighters as well as Syrian army positions.

"At about 4:30 am (0130 GMT) this morning, the Israeli enemy undertook an aerial aggression from the direction of the Mediterranean west of Latakia, targeting Aleppo International Airport," the source said, adding the attack damaged the runway.

Israel rarely comments on strikes it carries out in Syria, but has repeatedly said it will not allow its arch-foe Iran to expand its presence in the country.

An Israeli army spokesperson on Monday told AFP: "We do not comment on reports in the foreign media."

Syrian transport ministry official Suleiman Khalil said the damage centred on the only functioning runway, adding that "maintenance teams will start repair work today to return the airport to service as quickly as possible".

Flights were diverted to Damascus and Latakia airports, he told AFP.

The Syrian Observatory for Human Rights war monitor said the strikes also targeted weapons depots at the adjacent Nayrab military airport.

Israeli strikes have repeatedly caused the grounding of flights at the airports in Aleppo and the capital Damascus, both of which are controlled by the government.

- 'Cowardly' -

Syria's foreign ministry condemned Monday's strikes, calling them "cowardly".

It accused Israel of "threatening freedom of aircraft movement" and "the safety of international civil aviation", in a statement carried by SANA.

In early May, Israeli strikes on the Aleppo area killed four Syrian officers and three Iran-backed fighters and forced a halt to flights, according to the Britain-based Observatory.

Israel strikes put the airport out of service twice in March.

Three people were killed during a March 7 strike, while another air raid two weeks later destroyed a suspected arms depot used by Iran-backed militias at Aleppo airport, the war monitor reported.

Monday's strikes come a week after two fighters backing the Syrian government were killed in Israeli aerial assaults on sites near Damascus, said the Observatory, which relies on a network of sources on the ground in Syria.

Syria's war has killed more than 500,000 people, displaced millions and battered the country's infrastructure and industry since it began in 2011.

The war pulled in foreign powers and jihadists, and while the front lines have mostly quietened in recent years, large parts of the country's north remain outside government control.

With Iranian as well as Russian support, President Bashar al-Assad's government has clawed back much of the territory it had lost to rebels early in the conflict.