Iraqi government forces have been fighting with Sunni rebels for control of the country’s biggest oil refinery.

The sprawling Baiji refinery has been transformed into a battlefield as troops loyal to the Shi’ite led government struggle to hold Islamic insurgents.

The city lies squarely in territory captured in the past week by an array of Sunni groups, spearheaded by ISIL.

Shi’ite militias are coordinating with a regrouped military boosted by an injection of volunteers.

But many of those who’ve enlisted to help repel rebel forces have only rallied at the request of top Shi’ite cleric Ali al-Sistani.

The volunteers have been brought to Baghdad from across Iraq for a one week training course before being sent to cities controlled by the militants.

“We are ready and all the Iraqis are united as Shi’ites, Sunnis, Sabians and all other sects. We will remain loyal soldiers for a great Iraq,” said one volunteer.

According to official records, more than two million people have signed on to take up arms.

With the regular army loosing or giving up ground, the government is now relying on men like these for its survival.