Two American soldiers and a civilian, members of a joint delegation, were killed Saturday in Syria following an "ambush by a lone gunman" from the Islamic State organization, Washington announced.

Three other American soldiers were wounded in the attack, the U.S. military command for the Middle East (Centcom) said in a statement, adding that the gunman had been killed.

Pentagon spokesman Sean Parnell clarified on X that the civilian killed was an American interpreter.

The American contingent was in the Palmyra desert region for a "mission to support ongoing operations against ISIS/counter-terrorism in the region," he added.

A Pentagon official, speaking on condition of anonymity, also stated that the attack took place "in an area not controlled by the Syrian president."

This is the first time such an event has been reported in Syria since the takeover, a year ago, of an Islamist coalition that has made a rapprochement with the United States.

- "Advance warnings" -

Damascus, for its part, claimed that the forces of the international coalition, led by Washington, had not heeded warnings about the risk of infiltration by the Islamic State (IS) group.

"There were prior warnings from the internal security command to partner forces" in the Palmyra region, Interior Ministry spokesman Anwar al-Baba told state television.

US Defense Secretary Pete Hegseth called the perpetrator of the attack "savage" and issued a warning: "If you target Americans - anywhere in the world - you will spend the rest of your short, stressful life knowing that the United States will hunt you down, find you, and kill you without mercy."

The identities of the soldiers killed and the units to which they belonged will not be revealed for 24 hours, to allow time to inform their families, said Sean Parnell.

"The attack is currently under investigation," he added.

According to the official Syrian news agency Sana, "two members of the Syrian security forces" were also wounded in the shootings which targeted a "joint delegation".

A Syrian military official, speaking on condition of anonymity, indicated that the shooting broke out while Syrian and American officers were meeting at a Syrian security headquarters in Palmyra.

- Evacuations -

A witness in the city, who also requested anonymity, said he heard gunshots coming from inside the base.

Sana reported that helicopters had evacuated the wounded to the Al-Tanf base in the south of the country, where American troops are deployed.

According to the Syrian Observatory for Human Rights (SOHR), based in the United Kingdom but with a vast network of sources in the country, the visit of the American delegation to Palmyra "is part of a US strategy to expand its presence in Syria", and in particular in desert areas.

The jihadist group Islamic State had controlled the Palmyra region before being defeated in Syria by an international coalition in 2019.

Despite his defeat, his fighters, who have retreated into the vast Syrian desert, continue to carry out attacks sporadically.

During the visit of Syrian interim president Ahmad al-Sharaa to Washington last month, Damascus joined the US-led international anti-jihadist coalition.

American forces in Syria are deployed in areas under Kurdish control in the north, as well as at the Al-Tanf base, near the Jordanian border.