Islamic State loses $2m revenue as airstrikes destroy oil-tankers

A fleet of 168 oil tankers used by the Islamic State group to ferry illicit fuel in Syria were destroyed by US-led coalition airstrikes, officials said on Friday.

The tankers were destroyed near the desert city of Palmyra and resulted in an estimated lost revenue of more than $2 million.

"Stopping or severely hampering (IS) cash flow degrades their ability to fund the war effort in Iraq and Syria and terrorist attacks around the world," the coalition said in a statement.

The coalition said it is systematically targeting the oil infrastructure used by IS, under an operation dubbed 'Operation Tidal Wave II', named after a World War II mission to bomb oil refineries.

IS took Palmyra in May last year, and systematically destroyed temples and tower tombs at the town's UNESCO World Heritage site, before being pushed out by government forces. 

But the militants have attempted to retrieve control of the city this week, with reports suggesting clashes between IS and Syrian regime forces on the outskirts of Palmyra, eight months after losing it.

The militant group has suffered major losses across swathes of territories it controls in Syria and Iraq, as the US-led global coalition continues its offensive to retake Raqqa and Mosul.

On Saturday, the White House said it will deploy 200 soldiers to assist in the battle against the Islamic State group.

Raqqa, which has also served as a hub for militants plotting attacks abroad, is being isolated according to a plan, US Defence Secretary Ashton Carter said.