Crude oil prices have been on the increase in recent weeks, with concerns over disruption in supply driving up some international benchmarks to as high as $115 a barrel.
On Wednesday, militants from the Islamic State of Iraq and the Levant (ISIL) renewed attacks on Iraq's largest oil refinery at Baiji - forcing its closure and stoking fears over oil exports as some firms pulled foreign oil workers out of the country.
While all of Baiji's estimated output capacity of 320,000 barrels a day - a quarter of Iraq's refining capacity - has until now been used domestically, a prolonged shutdown could force the country to start importing oil and cut into global supplies.
Copyright, Gulf Daily News. 2014.