British Air Force Typhoon jets have joined forces with French aircraft in a joint strike on an subterranean weapons facility in Syrian territory used by the IS group, according to the UK's MoD.
The site, located using reconnaissance, was assessed as housing weapons and explosive materials, the statement said, and was positioned in mountainous terrain just above the ancient city of Palmyra in the heart of Syria.
"Our aircraft used Paveway IV guided bombs to target a several access tunnels providing entry to the facility... preliminary assessments suggest the target was engaged successfully," officials stated.
There was no evidence of any harm to civilians in the strike late on Saturday and each participating jet made a safe return, the ministry further stated.
The British jets were backed up by a Voyager aerial refuelling aircraft.
Daesh - also known as Daesh - enforced jihadist rule over significant areas in Iraq and Syria before its territorial defeat in 2019.
"This action demonstrates British leadership, and resolve to operate in unison with our allies, to stamp out any revival of IS and their harmful and extremist ideologies in the Middle East," Britain's Defence Chief the minister said.
UK warplanes have carried out patrols over Syrian airspace to "prevent any attempted resurgence" of Islamic State after its defeat at the Baghuz confrontation in 2019, the ministry said.
"I must thank all the members of British forces participating in this operation for their skill and their bravery," he said. "They were part of numerous British personnel deployed over the festive period. This operation, to eliminate dangerous terrorists who pose a risk to our way of life, demonstrates how British military are always on standby, continuously, protecting the UK at home and strong abroad."
During December, the US military carried out what it called a "major assault" on Islamic State objectives in Syria, after an assault resulted in the deaths of two US troops and a local interpreter in Palmyra.
The UN says IS still boasts an estimated 5,000 to 7,000 combatants in Syria and Iraq.