The Israeli raid "directly targeted an Iranian weapons shipment in the container yard," the Syrian Observatory for Human Rights said.

Syrian state media reported the strike on the container yard at Latakia port without specifying what was targeted.

The Observatory, a UK-based organisation with a wide network of sources on the ground across Syria, said the raid triggered a series of explosions.

It reported "huge material losses" but added there were no immediate reports of casualties.

According to the Syrian state news agency SANA, the strike occurred at 1:23 am (2323 GMT Monday).

"Our air defences repelled the Israeli aggression in Latakia," it said, adding that a number of containers caught fire in the strike.

Latakia is the northernmost of Syria's main ports, and lies around 230 kilometres (140 miles) north of Damascus.

Photos and footage published by SANA showed a fire in the yard but state television said later that firefighters had brought the blaze under control.

Israel rarely comments on the air strikes it carries out in Syria but has said repeatedly it will not allow its archfoe Iran to extend its footprint in Syria.

Since civil war broke out in Syria in 2011, Israel has carried out hundreds of air strikes on Syrian territory, targeting government positions as well as allied Iran-backed forces and Hezbollah fighters.

On November 24, Israeli missile strikes in the west of Homs province killed five people, according to the Syrian Observatory for Human Rights.

In two separate Israeli attacks in October, five pro-Iranian militiamen were killed near the Syrian capital Damascus while nine pro-government fighters were killed near the T4 airbase east of Palmyra in central Syria, the Observatory said.

Iran has been a key support of the Syrian government in the decade-old conflict.

It finances, arms and commands a number of Syrian and foreign militia groups fighting alongside the regular armed forces, chief among them Lebanon's powerful Hezbollah group.