BAGHDAD — Six months after the government triumphantly announced that Islamic State militants had retreated from Iraq’s largest refinery, the extremist group is again threatening to overrun the facility.
For weeks, soldiers, police officers and Shiite militiamen have struggled to hold their ground inside the Baiji oil complex during a brutal siege by the Islamic State. The militant group’s suicide bombers have relentlessly struck the perimeters of the refinery, about 150 miles north of the capital, and pushed deep inside the massive facility.
The Baiji operation shows how the Islamic State has remained resilient even after suffering setbacks at the hands of pro-government forces and losing fighters and equipment to U.S. airstrikes, according to analysts, Iraqi officials and militiamen. On Friday, the group also pushed into the heart of Ramadi, a city further to the south that has been fending off attacks by the Islamic State for more than a year.
“Daesh is still a relentless terrorist-military organization despite losing some ground,” said Saeed al-Jayashi, a Baghdad-based political analyst, using the Arabic acronym for the Islamic State.
As they swept through northern Iraq last summer, Islamic State fighters seized the city of Baiji and attacked the nearby refinery. A small group of Iraqi soldiers inside the facility held out for months as the Islamist fighters besieged it.
In November, Iraqi officials announced that a government counteroffensive had liberated the city and forced the militants to retreat from the refinery.
The success was short-lived. Militants reentered the city weeks later, and they stepped up attacks on the refinery as Iraqi forces focused on taking back the city of Tikrit, about 27 miles south of Baiji. Shortly after pro-government forces pushed the Islamic State from Tikrit last month, the militants seized much of the refinery.
The government rushed police and military reinforcements to the complex, preventing its all-out capture by the militants. Since the start of May, the U.S. military has carried out about 50 airstrikes in or around Baiji. But local officials say they are desperate for help.
“We need anyone who has weapons to come and fight in this operation,” said Raed al-Jabouri, the governor of Salahuddin province, where Baiji is located.
U.S. officials have acknowledged the difficult situation at the refinery. Earlier this month, Col. Steve Warren, a Pentagon spokesman, said the fight in Baiji was “flowing in the wrong direction.”
Baiji is important in part because of its strategic location on the road between Baghdad and Mosul. That route would serve as an important supply line for Iraqi troops if they seek to take the northern city in coming months, as planned.
The oil complex could also be a lucrative prize for the Islamic State. Before it was forced to shut nearly a year ago, the Baiji complex refined about a third of Iraq’s domestically consumed fuel, or about 175,000 barrels of oil daily.
Few analysts think Islamic State forces could get Baiji’s sophisticated machinery up and running. But tanks at the complex hold thousands of barrels of fuel that the group could sell or use, said Jassim al-Attiya, the deputy head of Salahuddin’s provincial council.
Jill Russell, a London-based military historian, said the Islamic State offensive is more about bolstering the group’s image than an attempt to be able to run the refinery. The militants have boasted that they control a growing caliphate spanning Syria and Iraq.
“If they don’t keep expanding, they’ll fall apart,” Russell said.
Because the Islamic State has grown so quickly, she noted, the group’s supply lines are weakly defended. “They’re definitely overstretched,” Russell said. And pro-government forces have struggled to exploit that vulnerability.
Ali Ibrahim, a colonel in Iraq’s federal police who is participating in the fight in Baiji, said dozens of Iraqi policemen and troops have been killed in recent weeks.
About three weeks ago, he said, pro-government forces secured the road to the refinery after months of clashes with the Islamic State and were able to bring in food, weapons, and police and military reinforcements.
But the militants then took the road and booby-trapped it with improvised explosive devices, Ibrahim said.
“Now we’re airdropping supplies to our forces in the refinery using helicopters,” he said.
The desperate circumstances at Baiji are producing unusual developments. Some Iranian-backed Shiite militias that have opposed U.S. involvement in the fight against the Islamic State are now saying that they want more coalition airstrikes in Baiji.
Khaled al-Khazraji, a member of the security committee of Salahuddin’s provincial council, said the Islamic State fighters have started setting fire to fuel-storage containers in an attempt to obstruct advances by pro-government forces.
The militias have provided much of the muscle in the Iraqi government’s efforts to win back territory from the Islamic State, often overshadowing the weak Iraqi army.
“We don’t understand why the coalition isn’t hitting the Islamic State harder,” said Thaer al-
Assadi, a spokesman for Kitaeb Jund al-Imam, an Iran-supported militia whose fighters are battling in Baiji.
Officials in Washington have expressed reservations about participating in military operations that involve the Shiite militias, which less than a decade ago were attacking American forces operating in Iraq.
Three of the most powerful militias, the Badr Organization, Kitaeb Hezbollah and Asaib Ahl al-Haq, are in negotiations with government officials over joining a renewed push to secure Baiji, a spokesman for Asaib Ahl al-Haq said.
Luay al-Khatteeb, an Iraq expert at the Brookings Doha Center, said the Islamic State fighters at Baiji would likely be defeated only if the militias join the battle.
“These Daesh guys are coming to die, and you need to fight them with an army that’s willing to die, not one that wants to go back home at the end of the battle,” he said.
“This is unconventional warfare, and you need an unconventional, ideological force to adequately oppose this group.”
Mustafa Salim contributed to this report.