WASHINGTON: Three US service members were killed and dozens wounded during an unmanned aerial drone attack on US forces stationed in northeastern Jordan near the Syrian border, President Joe Biden and US officials said on Sunday.

Biden blamed Iran-backed groups for the attack, the first deadly strike against US forces since the Israel-Hamas war erupted in October and sent shock waves throughout the Middle East.

“While we are still gathering the facts of this attack, we know it was carried out by radical Iran-backed groups operating in Syria and Iraq,” Biden said in a statement. At least 34 personnel were being evaluated for possible traumatic brain injury, a US official told Reuters, speaking on condition of anonymity.

Two different officials said some wounded US forces were medically evacuated from the base for further treatment.

Three US troops killed in drone attack on base in Jordan

Two US officials said the drone struck near the barracks early in the morning, which could explain the high number of casualties.

The Islamic Resistance in Iraq, an umbrella organization of hardline Iran-backed groups, claimed attacks on three bases, including one on the Jordan-Syria border.

The attack is a major escalation of the already tense situation in the Middle East, where war broke out in Gaza after Palestinian group Hamas’ attack on Israel on Oct. 7 which killed 1,200. Israel’s subsequent assault on Gaza has killed over 26,000 Palestinians, according to the local health ministry.

Since then, US forces have come under attack more than 150 times by Iran-backed groups in Iraq and Syria, causing at least 70 casualties prior to Sunday’s attack, most of them traumatic brain injuries. US warships have also been fired at by Iran-backed Houthi forces in Yemen, who are regularly attacking commercial ships passing through Red Sea waters off Yemen’s coast.