US forces carried out new strikes against two sites in Iraq early on Wednesday in retaliation for attacks by "Iran and Iran-backed groups," US Central Command said. 

The US military "conducted discrete, precision strikes against two facilities in Iraq," CENTCOM said on X, previously Twitter.

"The strikes were in direct response to the attacks against US and Coalition forces by Iran and Iran-backed groups," the post added, and come the day after a previous US air strike killed multiple Iranian-backed militiamen in Iraq.

Wednesday's attacks were carried out by US fighter aircraft on two facilities south of Baghdad, a Pentagon source said on condition of anonymity.

Hours earlier, a warplane struck a militia facility where Iranian-backed forces had fired a short-range ballistic missile at American and allied personnel in the country, the Pentagon said.

It was 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 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.

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.

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