Qais al Khazali, the leader of Asaib al Haq, a militia supported by Iran, at the Baiji oil refinery. The US detained Khazali, who is thought to have been involved in the murder of five US soldiers in Karbala in 2007, for two years before releasing him in 2009.

The Iraqi Security Forces (ISF) and their Shiite militia allies have reported major successes after launching an operation to recapture the central Iraqi city of Baiji last week,. The Islamic State is said to be holed up in just a pocket of the city after the Iraqi forces retook the Baiji oil refinery, the city center, and several districts.

According to Reuters last week, “The Hashid Shaabi militiamen and Iraqi army soldiers began their assault from the south.” Hashid Shaabi is the Arabic name for the Popular Mobilization Units (PMU), an umbrella under which a number of Shiite militias, including many that are backed by Iran, operate since banding together to fight the Islamic State last year. Just two days after launching the assault, the Iraqi forces reported recapturing 60 percent of the city. A day later, the nearby oil refinery, which has been contested for well over a year, was also reported to have been cleared of Islamic State fighters.

Iraqi forces have reported making more advances today, and claimed to have captured the city center and cleared the Tamim neighborhood. Fighters from the Liwa Ali al Akbar militia has also been photographed near the Al Fatah Mosque in the city center, with the group’s flag flying over what remains of the mosque. In another photo, Shiite flags can be seen on the road into Baiji. Other Shiite militias have also released photos and videos from the ongoing battle in the city.

Asaib Al Haq (League of the Righteous), Kataib Hezbollah (Hezbollah Brigades), and the Badr Corps, three of the larger Iranian-backed militias, have all released footage showing their troops taking part in the fighting. In one video from the Hezbollah Brigades, a huge convoy of the group’s fighters and Iraqi Army personnel can be seen moving into the nearby town of Siniyah. Hezbollah Brigades, which is backed by Iran, is a US-designated foreign terrorist organization that has been involved in killing American soldiers in Iraq.

Asaib al Haq has shown its fighters clearing out the oil refinery. Several of the top leaders of the Iranian-supported militia, which has also killed numerous American soldiers in Iraq, are listed as Specially Designated Global Terrorists.

The Badr Corps, which is also supported by Iran, has shown its forces and its leader, Hadi al Ameri, at Saddam Hussein’s old palace at Makhoul north of Baiji.

Other militias involved in the offensive include Harakat al Nujaba, which recently called for the expulsion of US troops from Iraq, and Kata’ib Imam Ali. Harakat al Nujaba is led by Akram al Kaabi, who is a Specially Designated Global Terrorist. Kata’ib Imam Ali is led by Shebl al Zaydi, a former commander in the Mahdi Army who is close to Iranian Qods Force commander Qassem Soleimani.

The US has provided air support to Iraqi forces in Baiji despite the direct involvement of Iranian-backed Shiite militias in the offensive. Today, the US military announced that “two strikes struck two separate ISIL [Islamic State] tactical units and destroyed an ISIL mortar system” near Baiji. In the past, US officials have downplayed the involvement of Iranian-backed militias whose leaders are listed as global terrorists in Iraqi military offensives, and has directly or indirectly provided air support for these groups.

The Iraqi government must regain control of Baiji if it plans on liberating Mosul, Iraq’s second largest city, from the Islamic State. Baiji sits alongside Highway 1, the main the road from Baghdad to Mosul.

Baiji has switched hands several times since the Islamic State launched its assault in northern and central Iraq in June 2014. The jihadist group took control of the city in its initial assault. Iraqi forces regained control of Baiji in December 2014, but lost it after several weeks of fighting. Iraqi troops and Shiite militias launched their last offensive in June 2015, and took control of the city briefly before losing it again.

The Islamic State has deployed scores of suicide bombs during the fighting in Baiji. Many of them were foreigners. An American is also said to have launched a suicide attack in the central Iraqi city.

Baiji hosts Iraq’s largest oil refinery. Much of the infrastructure at the facility is said to have been destroyed during the fighting over the past several months. [See LWJ report, Fighting at Iraq’s Baiji oil refinery is ‘flowing in the wrong direction’.]

Photos from Baiji and the surrounding areas:

Shiite flags purportedly flying near the entrance into Baiji:

Saddam Hussein’s old palace at Makhoul captured by the PMU:

Hadi al Amiri at the palace:

Liwa Ali al Akbar fighters near the Al Fatah Mosque in central Baiji:

Videos from Baiji:

Asaib al Haq at the Baiji oil refinery:

Hezbollah Brigades and the ISF moving into Al Siniyah:

Hezbollah Brigades showing its forces stopping Islamic State suicide bombers:

Harakat al Nujaba at Al Siniyah:

Liwa Ali al Akbar firing artillery into Baiji:

Liwa Ali al Akbar in house-to-house fighting:

Kata’ib Imam Ali also showing house-to-house fighting:

Video released by the Iraqi Ministry of Defense from Baiji:

Bill Roggio is a Senior Fellow at the Foundation for Defense of Democracies and the Editor of The Long War Journal. Caleb Weiss is an intern at the Foundation for Defense of Democracies and a contributor to The Long War Journal.

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