US Central Command did not specify the location of the night operation and said there were no civilian casualties in its initial assessments of the operation.
The statement described one of the two ISIS leaders targeted, Anas, as an “ISIS Syrian province official” involved in the plot of attacks in eastern Syria.
“The Islamic State continues to pose a threat to the security and stability of the region,” CENTCOM spokesman Joe Buccino said in the statement. “The deaths of these ISIS officials will disrupt the terrorist organization’s ability to continue plotting and carrying out destabilizing attacks in the Middle East.”
Kurdish forces also took part in the raid in the village of Al-Zer in eastern Deir el-Zour, the UK-based Syrian Observatory for Human Rights said. The activists refused to surrender before US helicopters fired on the house they were in, he added.
There are some 900 US forces in Syria supporting the Kurdish-led Syrian Democratic Forces in the fight against ISIS. They have frequently targeted IS militants, mostly in Kurdish-controlled parts of northeast Syria.
On November 30, IS announced that leader Abu al-Hassan al-Hashimi al-Qurayshi had been killed in action. The United States said al-Qurayshi was killed in an operation by rebel forces in the southern city of Daraa.
US troops and Kurdish fighters have resumed joint patrols in northeast Syria after a temporary halt following a series of Turkish airstrikes against Kurdish-led forces.