AKIPRESS.COM - Brent crude rose towards $114 a barrel on Wednesday as Sunni militants pushed forward in northern Iraq, striking a key refinery near Baghdad and stoking worries about oil exports from the key producer, Reuters said.

The rapid advance of militants in northern Iraq has led oil companies to pull foreign staff out of the country, fearing violence could spread to major oilfields concentrated in the south.

Further increasing tensions, Iranian President Hassan Rouhani said his country would not hesitate to defend Shi'ite holy sites in neighbouring Iraq.

Brent rose 20 cents to $113.65 a barrel by 0815 GMT. U.S. crude gained 35 cents to $106.71 a barrel after a draw in domestic stocks.

Worries about disruption to Iraq's supply drove up both benchmarks by more than 4 percent last week, the biggest weekly jump since July for Brent and since December for U.S. crude.

Sunni militants on Wednesday renewed their attack on Iraq's biggest oil refinery, Baiji, with machine-gun fire and mortars. The plant north of Baghdad has been shut and its foreign staff evacuated, although refinery officials said local staff remain in place and the military is in control of the facility.

"Crude prices are reacting to the headlines on the attack on the Baiji refinery," said Olivier Jakob, analyst at Zug, Switzerland-based consultancy Petromatrix.

"The insurgents are trying to create more instability. After the 2003 conflict, one of the first things the United States did was to get the refinery back running and petrol shortages would create more domestic instability," Jakob said.

Iraqi officials say the southern regions that produce some 90 percent of the country's oil are completely safe from the Islamic State of Iraq and the Levant (ISIL).