Syria: US base hit after tit-for-tat strikes kill contractor and pro-Iran fighters

A US air base in al-Omar oil field in northeast Syria's Deir Ezzor province was attacked on Friday morning, security sources told Reuters.

The White House later confirmed that no American personnel were injured in the attack, which it described as a reaction to a US retaliatory strike. 

On Thursday afternoon, a US contractor was killed and five American servicemen were wounded by a kamikaze drone attack "of Iranian origin" on a US-led coalition base near northeastern Syria's Hasakah, the US military said.

The US Central Command (Centcom) added that it responded by attacking facilities used by "groups affiliated with Iran's Islamic Revolutionary Guard Corps" (IRGC).

US Secretary of Defence Lloyd Austin said President Joe Biden ordered the strikes.

"The air strikes were conducted in response to today's attack as well as a series of recent attacks against coalition forces in Syria by groups affiliated with the IRGC," Austin said on Thursday.

The Syrian Observatory for Human Rights, a UK-based activist group that monitors Syria's conflict, said 14 Iran-backed fighters had been killed and six wounded.

"US strikes targeted a weapons depot inside Deir Ezzor city, killing six pro-Iran fighters, and two other fighters were killed by strikes targeting the desert of al-Mayadeen, and six others near Albu Kamal," said the Observatory's head Rami Abdel Rahman.

It is believed around 900 US troops are deployed in Syria. 

'Ineffective rocket fire'

Reacting to Friday's attack on the US base in al-Omar, White House National Security Council spokesperson John Kirby told MSNBC: "It is not uncommon, when we take a retaliatory strike like this, for them to answer right back with some ineffective rocket fire. And these were largely, completely ineffective."

He added that that there had been no casualties. 

According to the Observatory, Iran-backed groups near the eastern Syrian city of al-Mayadeen fired three misiles on Friday morning.  

Two missiles fell in al-Omar, Syria's largest oil field, while the third landed on a civilian house, it added.

"We're going to work to protect our people and our facilities as best we can. It's a dangerous environment," Kirby told CNN. 

According to US military figures, American troops have come under attack from Iran-backed groups around 78 times since the beginning of 2021. 

The 900 American troops, mostly in northeast Syria, are part of an international coalition fighting the Islamic State (IS) militant group, alongside the Kurdish-led Syrian Democratic Forces. 

IS still poses a danger in the region, despite losing large swathes of territory it ruled in Syria and Iraq in 2014, as shown in a deadly prison break last year and frequent attacks by sleeper cells against security forces and citizens in northeastern Syria.