President Donald Trump says “there will be very serious retaliation” after two U.S. service members and one American civilian were killed in an attack in Syria that the United States blames on the Islamic State group.

President Donald Trump said Saturday that there will be “very serious retaliation” after two US soldiers and one civilian interpreter were killed in an ambush in Syria on Saturday.

Two members of the U.S. Army and a civilian interpreter were killed, with three other Americans and two Syrians injured, in a shooting by a lone gunman Saturday in Syria.

The Department of War told Fox News Digital it is aware of reports that American troops have come under fire Saturday in the central Syrian town of Palmyra.

President Trump vowed retaliation Saturday after two U.S. Army soldiers and a civilian U.S. interpreter were killed in an attack in Syria, an incident the Pentagon said occurred during “a key leader engagement.

Injuries were reported in an attack that the Syrian government’s news agency said happened near the ancient city of Palmyra.