Baiji refinery
A view of Baiji oil refinery, about 112 miles north of Baghdad, January 22, 2009. Picture taken January 22, 2009 Reuters

Islamic militants advanced on Iraq’s biggest oil refinery Wednesday, a day after they took control of Mosul, the country’s second-largest city.

Jihadists with the al-Qaida splinter group, the Islamic State of Iraq and the Levant, or ISIL, drove into Baiji, in northern Iraq, and set fire to the courthouse and police station before freeing prisoners, security sources told Reuters. The militants then closed in on Iraq’s biggest oil refinery, located in Baiji, and reportedly told 250 men guarding the facility that they would offer them safe passage out of the refinery if they left their posts.

“Baiji has fallen,” Jabbar Yawer, a Kurdish armed forces spokesman, told Bloomberg.

Jasim al-Qaisi, a Baiji resident, said militants also warned police and soldiers to lay down their arms.

“Yesterday at sunset some gunmen contacted the most prominent tribal sheikhs in Baiji via cellphone and told them: ‘We are coming to die or control Baiji, so we advise you to ask your sons in the police and army to lay down their weapons and withdraw before [Tuesday] evening prayer,’” he said.

The Baiji refinery supplies oil to most of Iraq’s provinces. A worker there who works the morning shift told Reuters that he was not allowed to begin his job, adding that the night-shift workers were still at the refinery.

Also on Wednesday, militants reportedly stormed the Turkish consulate in Mosul and took diplomats hostage. Reuters reported that the diplomats were taken to ISIL's headquarters in the southern Iraqi city.

The siege on the oil refinery came a day after ISIL militants took control of Mosul. About 500,000 residents fled Iraq’s second-largest city amid the violence, according to the International Organization for Migration in Iraq, a UN-linked group.

Iraqi President Nouri al-Maliki offered weapons and equipment to any Iraqi who chooses to battle militants in Mosul on Tuesday. He also declared a state of emergency.