The US military has released footage and still photos of its air strikes on oil refineries controlled by Islamic State (IS) militants in eastern Syria.

The raids, carried out by US, Saudi and UAE aircraft, targeted 12 refineries in Syria on a third night of air strikes against the militants.

IS has seized large parts of Iraq and Syria in recent months.

Sales of smuggled crude oil have helped finance its offensive in both countries.

The US has launched nearly 200 air strikes against the militants in Iraq since August and on Monday began targeting IS in Syria.