A Jordanian armored personnel carrier and U.S. tanks take part in the

Caption

A Jordanian armored personnel carrier and U.S. tanks take part in the "Eager Lion" multinational military exercises in Jordan in September 2022. The U.S., Jordan and 28 partner nations took part in the exercises, representing one of the largest military exercises in the region. / AFP via Getty Images

Updated January 28, 2024 at 8:26 PM ET

President Biden is vowing to respond after a drone strike linked to Iran killed three U.S. service members and wounded at least 34 others. The number of wounded is expected to "fluctuate," according to U.S. Central Command.

The aerial drone struck American troops stationed in northeast Jordan near the Syrian border early Sunday.

"We had a tough day last night in the Middle East. We lost three brave souls," Biden said during a stop at Brookland Baptist church in West Columbia, S.C. After leading a moment of silence, Biden said: "And we shall respond."

The attack occurred at a support base known as Tower 22. A U.S. defense official told NPR the strike likely hit a barracks.

Tower 22 supports the Al-Tanf Garrison in southeastern Syria, where U.S. special operations have long operated in tandem with other countries in combating Islamic State militants. About 350 U.S. Army and Air Force personnel are deployed to the base.

Central Command said at least eight service members were evacuated out of Jordan to receive higher level care but they are in stable condition.

A U.S. official told NPR that the service members' injuries vary, with many suffering from traumatic brain injury. There are also reports of a spinal injury and at least one case of a shrapnel wound.

It marks the first deadly attack on U.S. forces in the Middle East since the Israel-Hamas broke out with the Hamas attacks on Israel on Oct. 7. The U.S. has been attempting to contain the conflict and prevent it from spreading further in the region.

Iranian officials deny the country had any involvement in the drone strike, according to the state-run IRNA news agency.

The Islamic Resistance in Iraq, a coalition of militias backed by Iran, claimed credit for the attack. The group called it revenge for America's military presence in the region and the Palestinian death toll in Gaza. More than 25,000 people have been killed in Gaza, according to Gaza's health ministry.

The Islamic Resistance in Iraq claimed to have attacked a total of four military bases on Sunday — three of which are U.S. bases in Syria and on the Syrian-Jordanian border, and one belonging to Israel. There has been no confirmation of other attacks from U.S. officials.

Defense Secretary Lloyd Austin described the service members as "brave Americans" who were deployed to northeastern Jordan to "work for the lasting defeat of ISIS."

"The President and I will not tolerate attacks on American forces, and we will take all necessary actions to defend the United States, our troops, and our interests," he said in a statement.

U.S. Central Command said it is in the process of notifying the families of the service members.

About 900 U.S. troops are stationed in Syria and 2,500 in Iraq, largely to help fight ISIS. Since the Israel-Hamas war started, Iranian-linked forces have carried out more than 140 attacks in those two countries.

Earlier this month, Central Command said a "number" of U.S. military personnel were evaluated for traumatic brain injuries after Iran-backed groups launched multiple ballistic missiles and rockets on an airbase in western Iraq. Most of the missiles were intercepted but at least one Iraqi service member was wounded, it added.

In December, three U.S. service members were injured, one critically, by a drone strike in northern Iraq. In response, the U.S. said it carried out multiple airstrikes against facilities used by militants.

NPR's Tom Bowman, Jane Arraf and Peter Kenyon contributed reporting.

Copyright 2024 NPR. To see more, visit https://www.npr.org.