The U.S. and Saudi Arabia have struck Iran-backed Shi'ite armed groups in Iraq, which the allies said were responsible for drone attacks on Saudi oil facilities.
HOW DID THE MILITIAS BECOME INFLUENTIAL IN IRAQ?
The Shi'ite groups sprang up as Tehran steadily entrenched itself in Iraqi politics and security matters after the U.S.-led invasion of Iraq toppled President Saddam Hussein in 2003.
The militias, with Iranian financial and military support, have become formidable forces that can rival the national army in firepower. They are also deeply enmeshed in Iraq's political, economic and social fabric, building business networks and taking seats in parliament and the government.
They are part of the Islamic Resistance in Iraq, an umbrella group of about 10 hardline Shi'ite armed factions that collectively command about 50,000 fighters and arsenals that include long-range missiles and anti-aircraft weapons, according to two security officials who monitor the militias' activities.
The Resistance group, a key pillar of Iran's network of regional proxy forces, has said it carried out dozens of missile and drone attacks on Israel and U.S. forces in Iraq and Syria since the Gaza war began in 2023.
The Trump administration has pressured Iraqi leaders to rein in these armed groups.
WHO ARE THE MOST POWERFUL GROUPS?
Kataib Hezbollah is the most powerful faction in the Islamic Resistance in Iraq.
One of the armed groups closest to Iran, it was founded by Abu Mahdi al-Muhandis in the mid-2000s. A U.S. air strike on Baghdad in 2020 killed Muhandis along with high-profile Iranian Major-General Qassem Soleimani.
After its founding, the group quickly developed a reputation for deadly attacks against military and diplomatic targets. It was accused of using a mixture of sniper, rocket and mortar attacks and roadside bombs.
Kataib Hezbollah has as many as 10,000 members, according to U.S. National Intelligence, and an arsenal of drones, rockets and short-range ballistic missiles, Iraqi officials and members of the group have said. The U.S. has struck Kataib Hezbollah positions, bases and training and logistics hubs several times over the years. The group has defied and challenged government statements calling for an end to attacks on U.S. forces.
It fought alongside other Shi'ite militias against mostly Sunni rebels during Syria's civil war.
The group has said it carried out high-profile kidnappings. The militia abducted Elizabeth Tsurkov, an Israeli Russian doctoral student, during her research trip to Iraq in 2023, according to Iraqi officials.
Asa'ib Ahl al-Haq (League of the Righteous), is headed by Qais Al-Khazali. Born in 1974, in the impoverished Sadr City area of Baghdad, Khazali has sought to soften his image in a quest to become one of Iraq's top politicians.
Khazali rose to prominence in the chaotic aftermath of the U.S. invasion. In 2007, he was arrested by American forces for his alleged role in an attack on a government compound in Karbala in the Shi'ite heartland of southern Iraq in which five U.S. soldiers were killed.
He was freed after about three years in an American prison in Iraq.
Khazali fought with fiery cleric Moqtada al-Sadr’s Mehdi Army against U.S. troops but formed his own armed group in 2006. He was among many militia fighters who went to northern Iraq to battle Islamic State after it seized large swathes of the country and imposed a reign of terror in 2014.
In 2020, Khazali said there was no longer a justification for thousands of U.S. troops to remain in Iraq since Islamic State had been defeated and that they would be an occupying force if they did not leave.
Though a militia commander, Khazali sat out militia attacks on U.S. military facilities during the Gaza war and was involved with Iraq’s education ministry.
He has denied his militia was involved in the deaths of thousands of people during Iraq's civil war from 2006 to 2007.
