The US has conducted "precision" air strikes in Syria on facilities used by the Iranian revolutionary guard, the Pentagon has said.
Secretary of Defence Lloyd Austin said the strikes were in response to "continued attacks" on US bases in Iraq and Syria by Iran-backed fighters.
At least eight pro-Iran fighters were killed, a UK-based war monitor said.
It is the third time since 26 October that the US has carried out such air strikes.
They come amid rising tensions in the region due to the Israel-Hamas war.
Mr Austin confirmed the air strikes in a brief statement on Sunday, saying they were conducted against a training facility and a safe house near the cities of Albu Kamal and Mayadin in eastern Syria.
He added the attacks were ordered by President Joe Biden "to make clear that the United States will defend itself, its personnel, and its interests".
The Pentagon did not provide any details on the damage caused by the strikes, but the Syrian Observatory for Human Rights (SOHR), a UK-based monitoring group, said eight members of Iran-backed militias were killed in the attack.
Seven others were injured, SOHR said. Most of the victims were non-Syrian nationals.
The group added that the strikes destroyed a weapons depot around Abu Kamal, near the Iraq-Syria border, and a rocket launch platform near Mayadin.
Iran-backed militias had also fired rockets at US bases overnight, SOHR said, though no one was killed.
The monitor has since reported a total of six attacks on International Coalition bases in Syria since Monday morning.
Pentagon officials said last week that Iranian-backed militias have attacked US bases and facilities in Iraq and Syria at least 41 times since the Israel-Hamas war began on 7 October.
They added that 56 US personnel have been injured in these attacks between 17 October and early November. The injuries are a combination of traumatic brain injury and minor injuries.
All personnel have since been treated and have returned to work, the Pentagon said.
American officials attribute the attacks to Iranian proxy groups operating in the region.
Iran is believed to have deployed hundreds of troops in Syria in support of President Bashar al-Assad in the country's 12-year civil war.
It has also armed, trained and financed thousands of Shia Muslim militiamen - mostly from Lebanon's Hezbollah movement, but also Iraq, Afghanistan and Yemen - who have also fought alongside the Syrian army.
On 27 October, the US carried out its first of the air strikes against two weapons and ammunition storage facilities in eastern Syria used by Iran-backed militias.
Another "self-defence strike" was conducted on 8 November on a facility in eastern Syria by two F-15 aircraft, the Pentagon has said.
With a war raging in the Gaza Strip and fears of an escalation into a regional conflict, there is an underlying worry that Iran and its proxies could soon get involved in the fight between Israel and Hamas, sparking a wider and even more serious war.
The US has emphasised that its recent airstrikes are not connected to what is going on in Gaza, that they were not done in any coordination with Israel, and that they are completely separate actions of self-defence.
American officials said they have been in contact with Iran and its proxies to warn against the escalation of fighting in the region.
"We aim to clarify that our military actions do not signal a change in our approach to the Israel-Hamas conflict, and we have no intentions of escalating conflict in the region," a senior Pentagon official has said in a statement.
Last month, President Biden sent a rare message directly to Iran's Supreme Leader Ayatollah Ali Khamenei, warning him not to target US troops in the Middle East.
Source: BBC
BDST: 0840 HRS, NOV 14, 2023
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