Two U.S. Army soldiers and a U.S. civilian who was serving as an interpreter were killed after shots were fired at U.S. and Syrian forces on a mission to a historic central town in Syria on Saturday, U.S. military officials said.

Pentagon spokesman Sean Parnell said in a post on X that the attack occurred as the soldiers were conducting a "key leader engagement." He said three other service members were injured in the incident.

"Their mission was in support of on-going counter-ISIS / counter-terrorism operations in the region," he said, adding that the soldiers' names, as well as identifying information about their units, will be withheld until 24 hours after the next of kin notification. "This attack is currently under active investigation."

U.S. Central Command said the attack was a "result of an ambush by a lone ISIS gunman in Syria," and that the "gunman was engaged and killed."

The shooting took place near Palmyra, according to Syria's state-run SANA news agency, which said two members of Syria's security force were wounded. Additional information on their condition was not immediately available.

No group has claimed responsibility for the attack, and the identity of the gunman has not been released.

U.S. Secretary of Defense Pete Hegseth said in a X post on Saturday that the "savage who perpetrated this attack was killed by partner forces."

"Let it be known, if you target Americans — anywhere in the world — you will spend the rest of your brief, anxious life knowing the United States will hunt you, find you, and ruthlessly kill you," he wrote.

Tom Barrack, the U.S. Ambassador to Turkey and special envoy for Syria, condemned the "cowardly terrorist ambush" on X. 

"We mourn the loss of three brave U.S. service members and civilian personnel and wish a speedy recovery to the Syrian troops wounded in the attack," Barrack wrote. "We remain committed to defeating terrorism with our Syrian partners."

The U.S. has hundreds of troops deployed in eastern Syria as part of a coalition fighting the Islamic State group.

Last month, Syria joined the international coalition fighting against ISIS as Damascus improved its relations with Western countries following last year's fall of President Bashar al-Assad when insurgents captured his seat of power in Damascus.

The U.S. had no diplomatic relations with Syria under Assad, but ties have warmed since the fall of the five-decade Assad family rule. The interim president, Ahmad al-Sharaa, made a historic visit to Washington last month, where he held talks with President Trump.

ISIS was defeated in Syria in 2019 but the group's sleeper cells still carry out deadly attacks in the country. The United Nations says the group still has between 5,000 and 7,000 fighters in Syria and Iraq.

U.S. troops, which have maintained a presence in different parts of Syria — including Al-Tanf garrison in the central province of Homs — to train other forces as part of a broad campaign against IS, have been targeted in the past. One of the deadliest attacks occurred in 2019 in the northern town of Manbij when a blast killed two U.S. service members and two American civilians, as well as others from Syria, while conducting a patrol.