US Central Command reported that American forces killed two ISIS militants in eastern Syria during a helicopter raid on Sunday.

In Syria and Iraq, ISIS sleeper cells continue to carry out deadly attacks. The group ruled large portions of both countries for several years but lost its last stronghold in 2019.

The US Central Command did not specify the location of the overnight operation and claimed in initial assessments that there were no civilian casualties.

Anas, one of the two targeted ISIS leaders, was described in the statement as an "ISIS Syria Province official" involved in plotting attacks in eastern Syria.

“ISIS continues to represent a threat to the security and stability of the region,” CENTCOM spokesman Joe Buccino said in the statement. “The death of these ISIS officials will disrupt the terrorist organization’s ability to further plot and carry out destabilizing attacks in the Middle East.”

Kurdish forces also participated in the attack on the village of Al-Zer in eastern Deir Ezzor, according to the Syrian Observatory for Human Rights, which is based in the United Kingdom. The militants refused to surrender before U.S. helicopters opened fire on the house they were in, the report added.

Approximately 900 American troops are in Syria to aid the Kurdish-led Syrian Democratic Forces in their fight against ISIS. They have frequently targeted ISIS militants, primarily in Kurdish-controlled areas of northeastern Syria.

IS announced on November 30 that its leader Abu al-Hassan al-Hashimi al-Qurayshi had been killed in battle. The US said al-Qurayshi was killed in an operation conducted by opposition forces in the southern city of Daraa.

After a temporary halt caused by Turkish airstrikes against Kurdish-led forces, US troops and Kurdish fighters resumed patrolling together in northeastern Syria.