Turkish President Tayyip Erdogan said on Sunday that Turkish intelligence forces killed IS leader Abu Hussein al-Qurashi in Syria.
"This individual was neutralised as part of an operation by the Turkish national intelligence organisation in Syria yesterday," Erdogan said in an interview with TRT Turk broadcaster.
Erdogan said the intelligence organisation had pursued Qurashi for a long time.
Syrian local and security sources said the raid took place in the northern Syrian town of Jandaris, which is controlled by Turkey-backed rebel groups and was one of the worst-affected in the February 6 earthquake that hit both Turkey and Syria.
The Syrian National Army, an opposition faction with a security presence in the area, did not immediately issue any comment.
One resident said clashes started on the edge of Jandaris overnight from Saturday into Sunday, lasting for about an hour before residents heard a large explosion.
The area was later encircled by security forces to prevent anyone from approaching the area.
IS selected al-Qurashi as its leader in November 2022 after the previous IS leader was killed in an operation in southern Syria.
The IS terror group took over vast swathes of Iraq and Syria in 2014, during the reign of Abu Bakr al-Baghdadi.
But IS lost its grip on the territory after campaigns by US-backed forces in Syria and Iraq, as well as Syrian forces backed by Iran, Russia and various paramilitaries.
Its remaining thousands of militants have in recent years mostly hid out in remote hinterlands of both countries, though they are still capable of carrying out major hit-and-run attacks.
The US-led coalition alongside a Kurdish-led alliance known as the Syrian Democratic Forces (SDF) is still carrying out raids against IS officials in Syria.
In some cases, senior IS figures have been targeted while hiding out in areas where Turkey has major influence.