Russia bombed a garrison used by U.S. troops to train Syrian fighters near Syria’s southern border with Jordan on Wednesday.
The fighters belonging to the Maghawir al-Thawra militia are part of an American-led coalition fighting the Islamic State terrorist group to prevent its resurgence.
The attack was carried out by a group of Russian jet fighters, including two SU-35s and one SU-24, a U.S. military official said, according to The Wall Street Journal.
The jets were seen flying over the al-Tanf area before they attacked a combat outpost at the garrison, the outlet reported.
No U.S. personnel were harmed in the attack, but property may have been damaged, CNN reported.
Russia had informed the U.S. of the attack in advance through a communication line both sides use to prevent accidental clashes.
The advance warning allowed the U.S. to warn the Maghawir al-Thawra fighters of the impending strike.
Since U.S. troops were already at a safe distance from the attack site, they did not have to move out before the strikes, officials told CNN.
The Wednesday airstrikes at the al-Tanf garrison were part of a series of attacks Russia conducted against the U.S.-led coalition in Syria this month, according to the Journal.
The attacks have worried military officials, who fear it could lead to a direct confrontation between U.S. and Russian forces, the outlet reported.
“We seek to avoid miscalculation or a set of actions that could lead to unnecessary conflict: that remains our goal,” Army Gen. Erik Kurilla, head of U.S. Central Command, said in a statement.
“However, Russia’s recent behavior has been provocative and escalatory,” he added.
Russia claimed that the Maghawir al-Thawra fighters had planted a roadside bomb to kill Russian forces, CNN reported, citing U.S. officials.
However, the U.S. believes those accusations are false and views them as an excuse to carry out the strike.
The al-Tanf garrison used to house as many as 200 American soldiers who helped train local fighters to combat Islamic State militants, according to the Journal.
This week, Russia sent two SU-34 jet fighters to the site of a U.S. raid in northeast Syria. U.S. forces were trying to apprehend a bomb manufacturer working for the Islamic State.
In response, the U.S. scrambled F-16 fighter jets, which warded off the Russian aircraft, U.S. officials said.
The “significant increase in provocation,” as one U.S. official described it, comes as the U.S. has given billions of dollars in weaponry to Ukraine to fight off a Russian invasion.