Defense Secretary Lloyd Austin, in an accompanying statement, said that at the direction of President Biden, U.S. forces in the region carried out airstrikes against facilities affiliated with the Islamic Revolutionary Guard Corps, an elite Iranian force that has targeted U.S. troops stationed in the Middle East on and off for years.
“The airstrikes 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. “As President Biden has made clear, we will take all necessary measures to defend our people and will always respond at a time and place of our choosing. No group will strike our troops with impunity.”
The Deir Ezzor 24 activist group, which has sources in the area, said that four members of what it describes as Iranian-linked militias were killed in the American strikes around the town of Deir al-Zour, and that others, including Iraqi citizens, were wounded.
Identities of the dead American and wounded personnel were not immediately disclosed.
Gen. Michael “Erik” Kurilla, who as the head of U.S. Central Command oversees all American military activity in the region, said in a statement that the United States has “scalable options” should tensions with Iran or it proxy forces escalate further. He described Thursday’s deadly strike as “another in a series of attacks on our troops and partner forces.”
While Biden has pledged to end American “forever wars,” he has maintained a force of about 900 U.S. troops in Syria and 2,500 in neighboring Iraq, both bolstered by hundreds of contractors. They are remnants of a larger force that, several years ago, guided local partner groups in a ferocious war to destroy the Islamic State’s self-declared caliphate.
That campaign was mostly successful, but the Islamic State and other armed groups remain active in the region, and so the American military mission endures. In February, four U.S. troops and a military working dog were wounded in an explosion during a raid on an Islamic State compound in Syria, U.S. officials said.
The statement released by the Pentagon on Thursday said that two U.S. troops were treated on-site for injuries suffered in the attack, and that three others as well as an American contractor were evacuated to medical facilities in Iraq for additional care. All are in stable condition, a U.S. official said, speaking on the condition of anonymity because the matter is considered highly sensitive.
President Donald Trump’s 2018 decision to withdraw the United States from a landmark nuclear deal with Tehran sparked rounds of increasingly deadly violence in Iraq as well.
Iranian-linked militias fired volleys of rockets into Baghdad’s U.S. Embassy and coalition military bases around the country, killing and wounding Iraqi and foreign troops. Trump responded by ordering the assassination of leading Iranian general Qasem Soleimani and airstrikes on militia-linked targets in both Iraq and Syria.
Tensions have ebbed in recent months, but the attacks remain a significant concern for the U.S.-led coalition.
Thursday’s retaliatory airstrikes were carried out by F-15 fighter jets, the official said. The Pentagon statement described its counterattack as “intended to protect and defend U.S. personnel,” calling the action “proportionate” and intended to “limit the risk of escalation and minimize casualties.”
Earlier Thursday, Kurilla told the House Armed Services Committee that Iran has launched 78 attacks on U.S. positions in Syria since January 2021. Tehran, he said, now possesses the largest and most diverse missile arsenal in the Middle East, and the largest and most capable unmanned aerial vehicle force in the region.
“The advancement of Iranian military capabilities over the past 40 years is unparalleled in the region; in fact, the Islamic Revolutionary Guard Corps of today is unrecognizable from just five years ago,” Kurilla told lawmakers.
Centcom reported in January that a self-detonating attack drone had struck the Tanf garrison, a base on the Iraqi border that coalition forces use to launch operations against the Islamic State. Two members of the Free Syrian Army partner force were injured, a spokesman said, and two other drones were shot down.
Thursday’s attack comes about a week after the general visited Hasakah, where a detention facility houses more than 5,000 Islamic State fighters, Kurilla told lawmakers. The population, he said, “represents a looming threat to Syria, the region and beyond.”
Kurilla said officials with the Syrian Democratic Forces, a group partnered with the United States to counter the Islamic State, see the detainees there as unrepentant and subject to further radicalization. One official described it to Kurilla as a “ticking time bomb,” the general said.
Louisa Loveluck in London contributed to this report.