Helicopter gunfire early Sunday killed nine people near a northwestern Syrian village where "groups linked to the ISIS group" were present, said a Britain-based war monitor with sources inside Syria.
The helicopters targeted a home and a car on the outskirts of the village of Barisha in the northwestern province of Idlib, the Syrian Observatory for Human Rights said, after US media said ISIS chief Abu Bakr al-Baghdadi was believed to be dead after a US military raid in the same province.
Observatory chief Rami Abdel Rahman said the helicopters likely belonged to the US-led military coalition that has been fighting the extremist group in Syria.
"We cannot confirm or deny that Baghdadi was in the area," he said.
An inhabitant of a camp for the displaced on the outskirts of Barisha said he had heard unidentified helicopters around midnight, followed by what he described as coalition air strikes.
They "were flying very low, causing great panic among the people," Ahmed Hassawi told AFP.
Long pursued by the US-led coalition, Baghdadi has been erroneously reported dead several times in recent years.
Officials told ABC News that biometric work was underway to identify those killed in the raid.
The White House announced Trump would make a "major statement" Sunday at 9:00 AM (1300 GMT), without providing details.