British Air Force Typhoon jets have operated alongside French aircraft in a combined operation against an subterranean weapons facility in Syria employed by the IS group, according to the UK Ministry of Defence.
The site, identified by surveillance, was assessed as containing munitions and bombs, the release indicated, and was located in mountains just above the ancient city of Palmyra in central Syria.
"The RAF jets used precision-guided Paveway IV munitions to strike a several entry passages leading to the site... initial indications indicate the objective was successfully hit," the MoD said.
There was no evidence of any civilian casualties in the strike late on Saturday and each participating jet made a safe return, the defence officials confirmed.
The British jets were backed up by a Voyager tanker plane.
IS - alternatively referred to as ISIS - established jihadist rule over significant areas in Iraq and Syria prior to its 2019 collapse.
"This strike underscores the UK's leading role, and resolve to stand shoulder to shoulder with allied nations, to stamp out any resurgence of IS and their dangerous and violent ideologies in the area," UK Defence Secretary the Defence Secretary said.
UK warplanes have carried out overwatch operations over Syrian airspace to "prevent any attempted resurgence" of Islamic State following its defeat at the climactic battle in Baghuz in 2019, the MoD reported.
"I want to thank every member of the UK armed forces who took part in this mission for their skill and their valour," the Defence Secretary said. "Including them were thousands of UK service members stationed over the holidays. This operation, to eliminate militants who pose a risk to our safety, shows how British military are ready to step up, all year round, protecting the UK within its borders and powerful internationally."
Last December, the American forces executed what it termed a "large-scale strike" on Daesh sites in the country, subsequent to an attack killed two American soldiers and a civilian linguist in Palmyra.
The United Nations estimates Islamic State still maintains an estimated 5,000 to 7,000 combatants in Syria and Iraq.
