The London-based group said two US helicopters conducted the operation in Beqres, a suburban area east of Dayr al-Zawr on Thursday morning, taking four Daesh members and a civilian from a house used as an arms depot.
According to the report, the five people transferred during the operation included a foreign bomb expert, three Egyptian Daesh members and a civilian.
Witnesses found shaved hair of the five individuals near the area, the observatory said, adding that after airlifting the Daesh members, troops blew up the arms depot.
The US and its allies have been conducting airstrikes against what are said to be Daesh targets inside Syria since September 2014 without any authorization from the Damascus government or a UN mandate.
The military alliance has repeatedly been accused of targeting and killing civilians. It has also been largely incapable of fulfilling its declared aim of destroying Daesh.
The US has long been accused of colluding with Daesh to provide safe passage and logistic support to the members of the Takfiri group in conflict zones.