US Central Command (Centcom) said on Monday that its forces in northern Syria had conducted "a unilateral helicopter raid" in the early morning targeting what it described as a senior "Islamic State" (IS) Syria leader "responsible for planning terror attacks in the Middle East and Europe."
"The raid resulted in the probable death of the targeted individual," Centcom said, also describing him as an operational planner for the group. "Two other armed individuals were killed on the target."
What we know about the US helicopter raid in Syria
The short statement said that no US troops were wounded, no helicopters damaged and that Centcom did not believe civilians were killed or injured in the operation.
A Central Command spokesman said additional details would be provided soon.
Syria's White Helmets, a civil defense group operating in opposition-held areas of northern Syria, said it transported two people wounded during the raid to a local hospital. Officials there later said the injured people had died.
A third person was killed when the US forces landed for the raid, the White Helmets said.
The Kurdish-led Syrian Democratic Forces, which partners with the US in anti-IS operations in northeast Syria, said that the operation was launched from a base in Kobani and targeted a military site belonging to what it described as a Turkish-backed armed opposition group near the Turkish border.
The British-based monitoring group the Syrian Observatory for Human Rights also reported a US helicopter raid and "violent clashes."
How active is IS in Syria?
The self-styled Islamic State rapidly took control of a large patch of territory in northern Syria and Iraq around 2014 and US and coalition forces intervened along with mainly Kurdish local fighters to push them back. By December, the group had lost around 95% of the land it had held at the peak of its power, once including cities like Mosul in Iraq and Raqqa in Syria.
"Though degraded, ISIS remains able to conduct operations within the region with a desire to strike beyond the Middle East," said General Michael "Erik" Kurilla, CENTCOM commander, using another acronym for the group. "We will continue the relentless campaign against ISIS."
On Sunday, the Syrian Observatory for Human Rights reported that an attack claimed by IS had killed at least 36 people. They included 19 civilians and 17 members of a militia loyal to the government, according to the report. The NGO said they were gathering truffles.
It also reported that five shepherds were killed and two others kidnapped by IS fighters in the east of the country.