An Iranian tanker was attacked off the coast of war-torn Syria Saturday, sparking a fire but not causing any casualties, the Britain-based Syrian Observatory for Human Rights said.

State news agency SANA quoted the oil ministry as saying the fire erupted after "what was believed to be an attack by a drone from the direction of Lebanese waters".

The fire was extinguished, it said.

The Observatory was unable to say whether it was a drone attack or a missile fired from a warship.

It was not immediately clear who was behind the attack near the Banias refinery in the regime-controlled coastal province of Tartus.

"It's the first such attack on an oil tanker, but the Banias terminal has been targeted in the past," Observatory head Rami Abdel Rahman said.

Early last year, Damascus said divers had planted explosives on offshore pipelines of the Banias refinery but the damage had not halted operations.

Israel has carried out hundreds of air strikes on Syrian soil since 2011, mostly targeting Iranian and Lebanese Hezbollah forces as well as allied Syrian government troops.

On Thursday, Israeli strikes killed a Syrian officer east of Damascus, in apparent retaliation for a missile fired hours earlier from Syria towards a secretive nuclear site in southern Israel. 

Before Syria's war, the country enjoyed relative energy autonomy, but production has plummeted during the war, pushing the government to rely on importing hydrocarbons.

Western sanctions on oil shipping, as well as US punitive measures against Iran, have complicated these imports.

Pre-war production was 400,000 barrels per day (bpd) in Syria.

But it stood at just 89,000 bpd in 2020, Syria's oil minister said in February, of which up to 80,000 came from Kurdish areas outside government control.