The raid took place Sunday near a small town along the Euphrates River valley, in the vicinity of the city of Deir al-Zour and deep in the heart of Islamic State territory, according to the officials and Syrian activist groups.
The troops, who landed on helicopters, spent about 90 minutes in the area, then left carrying Islamic State captives and bodies, according to witnesses quoted by the website Deir al-Zour 24, which monitors Islamic State activity in that province.
According to U.S. defense officials in Washington, the U.S. forces intercepted a vehicle carrying an Islamic State militant whom the U.S. military hoped to capture and interrogate. One official, who like others spoke on the condition of anonymity to discuss an operation whose details have not been publicly announced, said that a firefight broke out and the suspect, along with another person in the car, was killed. No Americans were injured.