Isis insurgents attacks Iraq's biggest oil eefinery

Islamist militants have attacked Iraq's largest oil refinery in the city of Baiji, 155 miles north of Baghdad, as Iran raised the prospect of direct military intervention to protect Shia holy sites.

A top security official told the Associated Press that fighters of the Islamic State in Iraq and the Levant (Isis) had begun their attack on the refinery late on Tuesday night.

The attack continued into Wednesday morning, with militants targeting it with mortar shells, starting a small fire on the periphery.

The refinery accounts for more than a quarter of the country's entire refining capacity, all of
which goes toward domestic consumption – petrol, cooking oil and fuel for power stations.

At the height of the insurgency from 2004 to late 2007, the Baiji refinery was under the control of Sunni militants who used to siphon off crude and petroleum products to finance their operations.

Isis has used its control of oilfields in Syria to boost its coffers.

Any lengthy disruption at Baiji risks long lines at the petrol pump and electricity shortages,
putting further pressure on the Shia-led government of the prime minister, Nouri al- Maliki.

Iraq's beleaguered prime minister has fired several top security commanders after Iraqi troops melted away before Isis militants as they captured the Mosul in the north, Iraq's second largest city.

Jihadi rebel forces have reached Baquba, less than 40 miles north of Baghdad, while fighting continues to rage further north in the city of Tal Afar.

State television late on Tuesday aired footage of army troops and armed volunteers disembarking from a transport C-130 aircraft at
an airstrip near the city.

Isis and disaffected Sunnis have threatened to march to Baghdad, the capital, and the Shia holy cities of Kerbala and Najaf in the worst threat to Iraq's stability since US troops left.

The three cities are home to some of the most revered Shia sites. Isis has tried to capture
Samarra, north of Baghdad, home to another major Shia shrine.