RAF Typhoon fighter aircraft have joined forces with French aircraft in a coordinated attack targeting an underground arms cache in Syrian territory used by the IS group, according to the UK Ministry of Defence.
The facility, located using reconnaissance, was assessed as containing munitions and bombs, the statement said, and was positioned in mountains just north of Palmyra in the heart of Syria.
"Our fighter planes employed laser-guided Paveway IV weapons to hit a series of entry passages leading to the facility... preliminary assessments indicate the target was engaged successfully," the MoD said.
There was no sign of any civilian impact in the operation late on Saturday and all the aircraft made a safe return, the MoD added.
The Typhoon fighters were assisted by a Voyager aerial refuelling aircraft.
IS - also known as ISIS - enforced extremist governance over parts of Iraq and Syria until 2019.
"This operation shows British leadership, and determination to work closely with our allies, to eradicate any re-emergence of the terrorist group and their dangerous and violent ideologies in the region," UK Defence Secretary the Defence Secretary stated.
RAF aircraft have carried out surveillance missions over Syria to "prevent any attempted resurgence" of the group subsequent to its routing at the climactic battle in Baghuz in 2019, the MoD reported.
"I must thank the personnel of the UK armed forces involved in this operation for their skill and their bravery," he commented. "They were part of thousands of British troops on duty over the holidays. This operation, to take out dangerous terrorists who threaten our security, demonstrates how our armed forces are ready to step up, all year round, keeping Britain secure domestically and strong abroad."
During December, the US military conducted what it called a "massive strike" targeting Islamic State objectives in Syria, following an attack claimed the lives of two American soldiers and a local interpreter in the Palmyra area.
The United Nations says IS still has an estimated 5,000 to 7,000 combatants in Iraq and Syria.
