British Air Force Typhoon jets have conducted a mission with French aircraft in a combined operation against an underground arms cache in Syria used by the IS group, according to the UK Ministry of Defence.
The site, identified by intelligence, was thought to be containing munitions and bombs, the announcement noted, and was positioned in hills just to the north of the ancient city of Palmyra in the heart of Syria.
"The RAF jets utilized laser-guided Paveway IV weapons to strike a number of approach shafts leading to the facility... initial indications suggest the strike was effective," the ministry announced.
There was no indication of any harm to civilians in the operation conducted Saturday night and each participating jet returned safely, the MoD added.
The British jets were backed up by a Voyager aerial refuelling aircraft.
Daesh - referred to as ISIS - enforced extremist governance over significant areas in Iraq and Syria prior to its 2019 collapse.
"This strike demonstrates our UK leadership, and commitment to stand shoulder to shoulder with allied nations, to stamp out any resurgence of the terrorist group and their violent and radical beliefs in the Middle East," Britain's Defence Chief the Defence Secretary remarked.
RAF aircraft have performed surveillance missions over Syrian airspace to "prevent any attempted comeback" of Islamic State after its military defeat at the climactic battle in Baghuz in 2019, the ministry said.
"I must thank all the members of our armed forces involved in this strike for their expertise and their bravery," Healey added. "They were among thousands of British personnel on duty over the holidays. This action, to eliminate terrorist threats who threaten our safety, shows how British military are prepared to act, throughout the year, ensuring Britain's security at home and influential overseas."
During December, the US military carried out what it called a "massive strike" on Islamic State objectives in the country, following an attack killed two US servicemembers and a local interpreter in the Palmyra area.
The UN estimates Islamic State still boasts roughly 5-7 thousand fighters in Iraq and Syria.