British Air Force Typhoon fighter aircraft have joined forces with French aircraft in a combined operation targeting an underground arms cache in Syrian territory employed by the IS group, according to the UK's MoD.
The facility, identified by surveillance, was believed to be containing munitions and bombs, the statement said, and was positioned in mountains just above the ancient city of Palmyra in Syria's central region.
"The RAF jets utilized Paveway IV guided bombs to strike a number of approach shafts down to the facility... initial indications are that the strike was effective," the ministry announced.
There was no sign of any civilian impact in the strike late on Saturday and each participating jet returned to base without incident, the ministry further stated.
The British jets were backed up by a Voyager refuelling tanker.
The Islamic State group - also known as ISIS - enforced extremist governance over parts of both Syria and Iraq prior to its 2019 collapse.
"This operation shows British leadership, and commitment to work closely with our partners, to stamp out any resurgence of Daesh and their violent and radical beliefs in the region," UK Defence Secretary John Healey stated.
British military aircraft have carried out patrols over Syrian airspace to "forestall any attempted comeback" of the group following its military defeat at the climactic battle in Baghuz in 2019, the authorities noted.
"I want to thank every member of our armed forces involved in this mission for their skill and their valour," Healey added. "They were among numerous British troops on duty over the holidays. This operation, to remove dangerous terrorists who endanger our way of life, shows how British military are prepared to act, all year round, ensuring Britain's security domestically and strong abroad."
Last December, the American forces executed what it described as a "large-scale strike" targeting IS targets in Syria, subsequent to an ambush killed two US troops and a civilian interpreter in the Palmyra area.
The UN reports Islamic State still maintains an estimated 5,000 to 7,000 combatants in Syria and Iraq.
