Royal Air Force Typhoon jets have conducted a mission with French aircraft in a coordinated attack on an underground arms cache in Syria employed by the IS group, according to the UK's MoD.
The site, located using intelligence, was assessed as containing munitions and bombs, the statement said, and was located in mountains just to the north of the historic site of Palmyra in the heart of Syria.
"Our fighter planes used laser-guided Paveway IV weapons to target a number of access tunnels down to the site... early reports are that the target was engaged successfully," the ministry announced.
There was no sign of any civilian casualties in the operation conducted Saturday night and every plane involved returned to base without incident, the MoD added.
The British jets were assisted by a Voyager aerial refuelling aircraft.
IS - alternatively referred to as Daesh - enforced extremist governance over significant areas in both Syria and Iraq before its territorial defeat in 2019.
"This strike shows our UK leadership, and resolve to operate in unison with our allies, to eradicate any resurgence of IS and their dangerous and violent ideologies in the region," Britain's Defence Chief the Defence Secretary said.
RAF aircraft have carried out surveillance missions over Syria to "forestall any attempted resurgence" of the group after its military defeat at the climactic battle in Baghuz in the year 2019, the MoD reported.
"I want to thank the personnel of British forces involved in this operation for their professionalism and their courage," he commented. "They were part of thousands of British troops stationed over Christmas and New Year. This operation, to eliminate militants who threaten our way of life, highlights how British military are prepared to act, throughout the year, keeping Britain secure at home and influential overseas."
Last December, the United States armed forces conducted what it termed a "massive strike" against Daesh sites in Syria, following an attack killed two American soldiers and a civilian linguist in the Palmyra area.
The UN says IS still has roughly 5-7 thousand fighters in Syria and Iraq.
