According to the Syrian Observatory for Human Rights war monitor, the strike hit an arms depot used by Iranian forces and killed seven people.

It would be the first attack in Syria since US President Donald Trump on Monday recognised the Golan Heights -- seized from Syria in the Six-Day War of 1967 -- as Israeli territory, a move which broke with decades of international consensus.

"Army air defences repel an Israeli air aggression that targeted a number of industrial sites in Sheikh Najjar industrial zone, northeast of Aleppo, and downed a number of the hostile missiles," Syria's official SANA news agency reported, citing an unnamed military source.

The Observatory said the Israeli bombardment hit "ammunition stores belonging to Iranian forces and allied groups, and caused huge explosions."

SANA said the strike caused only material damage but the Britain-based Observatory, which relies on a network of sources inside Syria, said seven people were killed.

It said the victims were guards protecting the targeted warehouses, which were used as ammunition depots by Iranian forces and allied militia.

The Observatory added the seven dead were neither Syrian nor Iranian but could not specify their nationalities.

A number of residents of Aleppo told AFP that the attack led to a power cut in the whole city. Power was restored hours later.

Israel has carried out hundreds of air strikes in Syria in the past few years targeting positions held by arch foe Iran and its Lebanese ally Hezbollah, with the goal of stopping Iran from entrenching itself militarily in the war-torn country.

Iran has been a major supporter of President Bashar al-Assad in the civil war that borke out in 2011.

In January, Israel hit a number of Iranian installations in the country, hours after intercepting a rocket fired from Syrian territory.

The Observatory said 21 people, mostly Iranians, were killed in those attacks.

In May last year, Israeli strikes killed 27 pro-regime fighters, including 11 Iranians, in strikes on dozens of Iranian targets inside Syria.

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