Washington said the strikes were in retaliation for an attack on its own personnel and SDF forces.
The Syrian Observatory for Human Rights said earlier that almost 40 foreign fighters allied to Syria's regime were killed in the raid in eastern Syria.
President Bashar al-Assad's army, with the help of Iran-backed militias including Hezbollah and Iraqi groups, drove ISIS from Albu Kamal and its environs a year ago, but the jihadis have since staged attacks there.
A spokesman for the coalition was not immediately available. They said 25 fighters were killed, three are missing and about 30 were wounded.More news: Weather service warns of hot Sunday and Monday in Central New York
The commander, who is not Syrian and spoke on condition of anonymity, said the strike killed and injured some Iraqi fighters, but did not give a toll.
The United States has about 5,200 troops in Iraq that are part of a coalition fighting Islamic State militants.
Syrian state TV is reporting that the USA -led coalition has struck a military position in the country's east, leaving several troops dead and wounded, allegations denied by a US official.
The U.S. denied a report from Syrian state media saying the U.S. bombed Syrian military positions in the eastern portion of the country.
The coalition's press office said it had heard reports that a strike in the area had killed and wounded members of a pro-regime Iraqi militia, but denied it was responsible.More news: PM Modi salutes indomitable spirit of Afghanistan on Test debut
An Iraqi paramilitary force Monday accused the United States of killing 22 of its fighters in an overnight air raid just inside Syria's border with Iraq that a monitor said left dozens dead.
The two forces have mostly avoided crashing into each other thanks to a de-confliction line that runs across the province along the winding Euphrates River. The overnight attacks took place on the western side.
The buffer has largely been successful in keeping the two offensives apart, but there have been exceptions. Israel certainly is no stranger to attacking Syria, and some Hezbollah fighters were killed in the incident.
"For the first time in four years, Dashisha, a notorious transit town for weapons, fighters, and suicide bombers between Iraq and Syria, is no longer controlled by ISIS terrorists", Brett McGurk, the U.S. president's special envoy for the war against IS, said on Monday.More news: San Antonio Spurs' Kawhi Leonard demands trade