US forces carried out a "large airborne operation" near Deir al-Zor in eastern Syria on Monday at dawn, Syrian state news agency SANA said.
The American forces landed in the town of Busayra, east of Deir al-Zor, and "kidnapped a number of civilians," it said.
There was no independent confirmation of the report.
In Washington, the Pentagon said U.S-led coalition forces had carried out an operation with the Syrian Democratic Forces (SDF) in Busayra that killed four Islamic State fighters, including one wearing a suicide vest, but there had been no detentions.
It added that there was a separate unilateral operation by the SDF but did not say whether anyone was detained by them.
The province of Deir al-Zor, along the Iraqi border, is a strategic supply route for Iranian-backed militias who regularly send reinforcements into Syria to support President Bashar al-Assad against insurgents seeking to topple his family rule.
US forces are deployed at a base in the al-Tanf region, south of Deir al-Zor, as part of a combat mission against Islamic State militants who continue to wage a low-level insurgency in Iraq and Syria.
The base was attacked by drones on October 20, with no casualties being reported. The attack was seen as an escalation between Iranian-backed militias and US forces, as the use of drones in Syria against US forces is relatively rare.