"Multiple" coalition warplanes have destroyed scores of oil tankers used by the Islamic State group, according to the US military.

Some 83 of the vehicles were struck during Sunday evening's airstrikes in eastern Syria, according to Pentagon spokesman Matthew Allen.

The raids are said to have happened near Albu Kamal, in Deir Ezzor province, along the border with Iraq.

Mr Allen said: "This strike is a component of ongoing Tidal Wave II operation designed to attack the distribution network of (Islamic State's) oil-smuggling operation and degrade their capacity to fund their operations."

The mission is named after a World War II operation to bomb oil refineries.


Image: Helped by airstrikes, Kurds took the town of Kobani from IS in January

It was not immediately clear if the drivers of the oil tankers in Sunday's raids were forewarned.

In two airstrikes last year, the US said it dropped pamphlets warning drivers, who were apparently not Islamic State members, of the imminent attack.

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In those desert raids, the Pentagon said coalition planes had destroyed about 400 tankers.

At the weekend coalition-backed forces defeated the jihadists in the northern Syrian town of Manbij, according to AFP news agency reporters at the scene.

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Manbij is seen as key to an advance on Raqqa, the self-styled caliphate's de facto capital, which the Arab-Kurdish alliance known as the Syrian Democratic Forces is also vowing to take.

Iraqi forces have already retaken the cities of Tikrit, Ramadi and Fallujah.

US Airstrikes On the strategic Syrian town of Kobani

They are currently fighting to oust the Islamic State from Mosul, Iraq's second city.

More than 290,000 people have now died in Syria's civil war since it broke out in 2011, according to a monitoring group, the Syrian Observatory for Human Rights.

There have been more than 14,300 air strikes by coalition forces since the campaign began two years ago.