RAF Typhoon fighter aircraft have joined forces with French warplanes in a joint strike on an subterranean weapons facility in Syria operated by the IS group, according to the UK Ministry of Defence.
The site, identified by intelligence, was thought to be storing arms and explosives, the announcement noted, and was located in mountainous terrain just north of Palmyra in Syria's central region.
"The RAF jets employed precision-guided Paveway IV munitions to hit a several entry passages down to the depot... preliminary assessments suggest the strike was effective," the MoD said.
There was no indication of any harm to civilians in the attack on Saturday evening and each participating jet returned safely, the MoD added.
The British jets were backed up by a Voyager aerial refuelling aircraft.
The Islamic State group - referred to as Daesh - imposed militant control over significant areas in Syria and Iraq before its territorial defeat in 2019.
"This strike underscores the UK's leading role, and resolve to work closely with our allies, to stamp out any resurgence of the terrorist group and their violent and radical beliefs in the Middle East," Britain's Defence Chief John Healey said.
RAF aircraft have carried out patrols over Syria to "forestall any attempted comeback" of Islamic State subsequent to its routing at the Baghuz confrontation in 2019, the ministry said.
"I must thank the personnel of the UK armed forces involved in this mission for their professionalism and their valour," he commented. "Including them were thousands of UK service members stationed over the festive period. This mission, to eliminate militants who pose a risk to our security, highlights how British military are prepared to act, throughout the year, protecting the UK at home and strong abroad."
During December, the American forces conducted what it called a "large-scale strike" on Islamic State objectives in the country, after an attack claimed the lives of two American soldiers and a civilian interpreter in Palmyra.
The United Nations estimates Islamic State still has between 5,000 and 7,000 militants in Iraq and Syria.
