The operation was "focused on ISIL leadership" and was conducted by a US special operations unit tasked with tracking down top jihadist operatives, Navy Captain Jeff Davis said.
Davis said, however, that reports by the Syrian Observatory for Human Rights, an independent monitor, that 25 jihadists had died in the raid were "grossly exaggerated."
He said the raids were carried out by the "Expeditionary Targeting Force" (ETF), an elite unit deployed to Iraq.
This kind of raid is aimed at eliminating jihadists as well as intelligence-gathering to conduct further operations, Davis said.
According to the Syrian Observatory of Human Rights and the Syrian Democratic Forces, a US-backed coalition of Arab and Kurdish forces, at least four helicopters, including Apache attack helicopters, were used in the operation.
A commander of the SDF said the attack targeted vehicles driven by senior IS fighters coming from Raqa, killing several and capturing other. Davis denied that prisoners were taken, saying there was "no detention from this operation."
A Syrian army official said military radars had detected the operation but could not identify the nationality of the aircraft.
The United States has been leading a campaign against IS in Syria since September 2014.
Deir Ezzor is Syria's second biggest province after Homs. Since early 2015, jihadists have besieged the provincial capital, also called Deir Ezzor, home to some 200,000 people.
According to the Observatory, the raids killed 14 IS members traveling on a bus and 11 in a firefight when a water facility was targeted.
