US carries out retaliatory airstrikes against Iranian-backed militia facilities in Syria

President Joe Biden has launched airstrikes on Friday against Iranian-backed fighters in Syria, as he used his first military operation since being elected to retaliate for a rocket strike on a US base in Iraq.

An Iraqi militia official told Reuters news agency that one fighter was killed in the strike, though there also reports in Syria of at least a dozen deaths and many injuries.

The strike was carried out in eastern Syria and targeted infrastructure being used by Iran-funded militia groups.

It follows a rocket attack by Iranian-backed militia groups on US bases in Erbil, which killed a civilian contractor and wounded several others.

By choosing to strike pro-Iran forces operating in Syria, rather than in Iraq, the White House hopes to avoid stoking anti-American tensions in the latter country, where the militia groups are gaining influence.

It also allows the Iraqi authorities to continue their own investigation into the Erbil rocket strike without a further escalation in violence.

"At President (Joe) Biden’s direction, US military forces earlier this evening conducted airstrikes against infrastructure utilised by Iranian-backed militant groups in eastern Syria," Pentagon spokesman John Kirby said in a statement.

"President Biden will act to protect American and Coalition personnel. At the same time, we have acted in a deliberate manner that aims to de-escalate the overall situation in both eastern Syria and Iraq," Mr Kirby said.

He added that the strikes destroyed multiple facilities at a border control point used by a number of Iranian-backed militant groups, including Kata'ib Hezbollah (KH) and Kata'ib Sayyid al-Shuhada (KSS).

Defence Secretary Lloyd Austin said he was "confident in the target that we went after, we know what we hit".

Speaking shortly after the airstrikes, he added: "We're confident that that target was being used by the same Shia militants that conducted the strikes," referring to the Feb. 15 rocket attack in northern Iraq.

Mr Austin said he recommended the action to the US president.

"We said a number of times that we will respond on our timeline," Mr Austin said. "We wanted to be sure of the connectivity and we wanted to be sure that we had the right targets."

A US official said the decision to carry out these strikes was meant to send a signal that while the United States wanted to punish the militias, it did not want the situation to spiral into a bigger conflict.

It was not clear what damage was caused and if there were any casualties from the US strike.

Retaliatory US military strikes have occurred a number of times in the past few years.

The rocket attacks on US positions in Iraq were carried out as Washington and Tehran are looking for a way to return to the 2015 nuclear deal abandoned by former US President Donald Trump.

It was not clear how, or whether, the strike might affect US efforts to coax Iran back into a negotiation about both sides resuming compliance with the 2015 nuclear deal.

In the Feb. 15 attack, rockets hit the US military base housed at Erbil International Airport in the Kurdish-run region killing one non-American contractor and injuring a number of American contractors and a US service member.

Another salvo struck a base hosting US forces north of Baghdad days later hurting at least one contractor.

Rockets hit Baghdad’s Green Zone on Monday which houses the US embassy and other diplomatic missions.

Earlier this week, the Kata'ib Hezbollah, one of the main Iran-aligned Iraqi militia group, denied any role in recent rocket attacks against US targets in Iraq.

Some Western and Iraqi officials say the attacks, often claimed by little-known groups, are being carried out by militants with links to Kata'ib Hezbollah as a way for Iranian allies to harass US forces without being held accountable.

Since late 2019, the United States carried out high-profile strikes against the Kataib Hezbollah militia group in Iraq and Syria in response to sometimes deadly rocket attacks against US-led forces.

Under the Trump administration, the escalator back-and-forth stoked tensions, culminating in the US killing of Iranian military leader Qassim Soleimani and a retaliatory Iranian ballistic missile attack against US forces in Iraq last year.