British Air Force Typhoon FGR4s have operated alongside French aircraft in a combined operation against an underground arms cache in Syria used by the Daesh militant organization, as stated by the UK Ministry of Defence.
The site, identified by intelligence, was believed to be housing weapons and explosive materials, the statement said, and was located in hills just above Palmyra in the heart of Syria.
"Our aircraft used precision-guided Paveway IV munitions to strike a series of approach shafts down to the facility... initial indications are that the strike was effective," the MoD said.
There was no sign of any civilian casualties in the strike late on Saturday and each participating jet returned to base without incident, the MoD added.
The British jets were backed up by a Voyager aerial refuelling aircraft.
IS - also known as Daesh - enforced jihadist rule over parts of Iraq and Syria until 2019.
"This action underscores British leadership, and resolve to work closely with our allies, to eliminate any resurgence of Daesh and their harmful and extremist ideologies in the area," UK Defence Secretary John Healey stated.
UK warplanes have conducted surveillance missions over Syria to "deter any efforts to regroup" of the group subsequent to its military defeat at the climactic battle in Baghuz in 2019, the authorities noted.
"I must thank all the members of British forces involved in this strike for their expertise and their courage," he said. "They were among a great many British personnel on duty over the holidays. This mission, to eliminate militants who threaten our way of life, highlights how UK forces are ready to step up, throughout the year, keeping Britain secure at home and strong abroad."
Last December, the US military executed what it termed a "major assault" targeting Islamic State objectives in Syria, after an ambush killed two US troops and a civilian interpreter in the Palmyra area.
The UN reports Daesh still has roughly 5-7 thousand fighters in both countries.
