U.S. forces were attacked at an air base west of Baghdad on Tuesday and a U.S. military aircraft responded in self-defence, killing a number of Iranian-backed militants, U.S. officials said.

Ain al-Asad air base was attacked by a close-range ballistic missile that resulted in eight injuries and minor damage to infrastructure, two U.S. officials said.

The United States responded using an AC-130 aircraft already in the air and it hit an Iranian-backed militia vehicle and a number of personnel involved in the attack, said Sabrina Singh, a Pentagon spokesperson.

She added that the aircraft was able to determine the point of origin and hit the militants because they were able to keep an eye on their movements.

This is the first public retaliation on Iraqi territory to the recent militant drone and missile attacks on U.S. troops, but Singh said there had been previous responses that had not been announced.

The United States had so far limited its response to the 66 attacks against its forces in Iraq and neighbouring Syria, claimed by Iran-aligned Iraqi militia groups, to three separate sets of strikes in Syria.

At least 62 U.S. personnel have suffered minor injuries or traumatic brain injuries in the attacks.

The attacks began on Oct. 17 and have been linked by Iraqi militia groups to U.S. support for Israel in its bombardment of Gaza following attacks by Palestinian militant group Hamas on Israel.

The attacks against U.S. targets have ended a year-long unilateral truce that Iraqi factions, some formed in the aftermath of the 2003 U.S. invasion to fight U.S. troops and others in 2014 to fight Islamic State, declared with Washington.

Social media accounts linked to Iran-aligned Iraqi militias published a statement in the name of the "Islamic Resistance in Iraq" mourning a member who they said had been killed in battle against U.S. forces on Tuesday, without elaborating.

His killing is the first reported casualty in Iraq linked to the Gaza war, which has drawn in other factions in Iran's network of regional militias, known as the Axis of Resistance, such as Lebanon's Hezbollah.

The United States has 900 troops in Syria and 2,500 in Iraq on a mission it says aims to advise and assist local forces trying to prevent a resurgence of Islamic State, which in 2014 seized large swaths of both countries before being defeated.

US strike kills Iran-backed forces in Iraq.

Iraqi mourners in Baghdad carry the coffin of a Kataeb Hezbollah fighter who was also part of the 'Islamic resistance in Iraq,' which has claimed recent attacks against US troops in Iraq and Syria, and who is believed to have died in a US air strike.

A US warplane killed multiple Iranian-backed militiamen in Iraq after they fired a short-range ballistic missile at American and allied personnel in the country, the Pentagon said Tuesday.

It is the first time the United States has announced a strike on Iranian proxy forces in Iraq since targeting Tehran-linked sites in Syria on three occasions in recent weeks, in response to a spike in attacks on American personnel.

"We can confirm an attack last night by Iran-backed militias using a close-range ballistic missile against US and coalition forces at Al-Asad Airbase, which resulted in eight injuries and some minor damage to infrastructure," Pentagon spokesman Brigadier General Pat Ryder said in a statement.

The Ain al-Asad Air Base is located in the desert of Iraq's Western Anbar province and hosts forces of the US-led coalition fighting the Islamic State (IS) group in Iraq.

"Immediately following the attack, a US military AC-130 aircraft in the area conducted a self-defense strike against an Iranian-backed militia vehicle and a number of Iranian-backed militia personnel involved in this attack. This self-defense strike resulted in several enemy KIA (killed in action)," Ryder said.

The surge in attacks on American troops is linked to the latest war between Israel and Hamas, which began on October 7 when militants from the Palestinian group carried out a shock cross-border attack from Gaza that Israeli officials say killed about 1,200 people, most of them civilians.

Israel has responded with a relentless air, land and sea campaign against Hamas that the Gaza health ministry says has killed more than 14,000 people, also mostly civilians.

Those deaths have sparked widespread anger across the region, and Israel's campaign against Hamas has repeatedly been cited as justification for attacks on American personnel in Iraq and Syria that have left scores of US troops injured.

Deputy Pentagon Press Secretary Sabrina Singh told reporters in Washington that US forces "have been attacked approximately 66 times since October 17 -- 32 separate times in Iraq and 34 separate times in Syria."

She said the attacks have resulted in approximately 62 injuries to US personnel, but that number did not include the eight cited by Ryder.

- Tracking militants -

While American forces have been targeted in both Iraq and Syria, Washington had until now only responded with strikes in Syria in an apparent bid to avoid inflaming political tensions in Iraq, which the United States invaded in 2003 and where Iran wields substantial influence.

Singh said the militants were targeted in Iraq "because the AC-130 was able to determine the point of origin from where the close-range ballistic missile was... fired to the base" and then tracked the militants in their vehicle.

She added it was the first time such a munition had been used against US forces since the wave of attacks began on October 17.

A source from the Hashed al-Shaabi or Popular Mobilization Forces -- mainly pro-Iranian units now integrated in the regular armed forces -- had earlier confirmed that a strike on a vehicle had killed one fighter and wounded three others.

The strike hit a vehicle belonging to a pro-Iranian group in a convoy traveling through Abu Ghraib, 30 kilometers (20 miles) west of Baghdad.

A group called "the Islamic resistance in Iraq" said Tuesday that one of its fighters was killed, without elaborating on the circumstances and without saying if he was killed in Abu Ghraib.

His funeral was held in a Baghdad mosque Tuesday and hundreds of fighters from the Hashed al-Shaabi attended, according to an AFP journalist.

There are roughly 2,500 American troops in Iraq and some 900 in Syria as part of efforts to prevent a resurgence of the Islamic State group.

AC-130 Ghostrider Gunship Strikes Iranian-Backed Militia In Iraq.

A U.S. Air Force AC-130J Ghostrider gunship struck a vehicle Tuesday near Baghdad involved in recent attacks on the Al-Asad airbase in Iraq, a U.S. official told The War Zone Tuesday. It was the first time the U.S. has struck a target in Iraq since the outbreak of the Israel-Hamas war Oct. 7.

At least one member of the Iranian-backed Kataib Hezbollah militia was killed in the attack, said the official, speaking on condition of anonymity to discuss operational details. The official did not specify what role the vehicle or occupants had in the attacks on Al-Asad.

A U.S. military official told The War Zone that "at least one member of a hostile force belonging to an Iranian-backed militia" was killed when the U.S. responded to an attack on Al Asad today that injured several U.S. troops and caused minor damage to infrastructure.

It was the 65th such attack on U.S. forces in Iraq and Syria since Oct. 17, according to the Pentagon. It was also the third time, including Oct. 21 and Oct. 17, that U.S. troops have been injured by attacks on Al Asad, according to the Pentagon, which said the base has struck at least 15 times by drones and rockets since Oct. 17.

The U.S. military official, also speaking on condition of anonymity for the same reasons, could not immediately say how many troops were injured or offer details about what kind of injuries. That official would not say how the U.S. strike was carried out nor what role the vehicle or occupants played in the attack on Al Asad.

This marks the fourth known U.S. airstrike against Iranian-backed militias since Oct. 26 and the first in Iraq, as well as the first by a Ghostrider. The previous three attacks - Nov. 12, Nov. 8  and Oct. 26 - were carried out by Air Force fighters on targets in Syria.

Open source trackers began reporting seeing a Ghostrider flying patterns over west Baghdad last night. The fact that it was doing so with its transponder on was very peculiar.

The latest attack on Al Asad was claimed by a loose-knit group of those militias calling itself the Islamic Resistance. There were also three reported over the weekend, two in Syria and one in Iraq.

The group said one of the fighters associated with it, Fadil Al-Maksusi, was killed. He belonged to Kataib Hezbollah and was killed in the airstrike, Atlas News reported.

The Pentagon says the attacks on U.S. forces since Oct. 17 have been fairly evenly split, with 31 in Iraq and 34 in Syria. They have been carried out "by a mix of one-way attack drones and rockets," a U.S. official said. "Most of these attacks were successfully disrupted by our military. Most failed to reach their targets, thanks to our robust defenses."

Still, more than 60 troops have been injured in these attacks, including the ones in the most recent attack on Al Asad. Deputy Pentagon Press Secretary Sabrina Singh told reporters Nov. 16. About 27 troops were evaluated for traumatic brain injury and 32 for non-serious injuries and all have returned to duty, she said.

In January 2020, Al Asad was struck by 11 Iranian Qiam-1 short-range ballistic missiles had hit Al Asad in response to an attack that killed Islamic Revolutionary Guard Corps leader Qassam Soleimani.

As for the platform involved here, the AC-130J, it's Air Force Special Operations Command's flying arsenal ship equipped with 30mm Bushmaster chain gun, a 105mm Howitzer and a wide variety of air-to-ground guided weapons. Its sensor and communications suite, as well as its long loitering time and surgical air-to-ground arsenal, make it extremely capable when it comes to finding and attacking targets of opportunity in lower threat airspace, especially at night. Y

This is a developing story. We will update it when there is more news to report about the attack.

Update: 2:29 PM EDT -

The strike by the AC-130J Ghostrider was the first attack on Iranian-backed militias that was not pre-planned, Singh told reporters Tuesday.

The aircraft was already in the air over Al-Asad at the time and was responding to an attack, she said. The three prior reported attacks were all planned in advance. Singh declined to say why the gunship was in the air, but that it had "eyes on" the militia attack as it unfolded.

In addition, she said this was the first attack on U.S. personnel since Oct. 17 by a close-range ballistic missile. She declined to specify what kind, but the official U.S. definition is a missile with a range of less than 300 km (about 186 miles). Singh also said that several militia members were killed in the strike, the first time the U.S. has confirmed casualties in its responses.

Singh also updated the total number of strikes against U.S. forces and the number of injuries that have resulted.

"U.S. forces have been attacked approximately 66 times since Oct. 17," Singh said. "It's 32 separate times in Iraq and 34 separate times in Syria. U.S. personnel have sustained approximately 62 injuries. But this does not include any injuries from last night's attack, but they are still being evaluated."