British Air Force Typhoon jets have operated alongside France's air force in a combined operation on an underground arms cache in Syria used by the Islamic State group (IS), according to the British defence ministry.
The site, identified by reconnaissance, was thought to be storing arms and explosives, the statement said, and was located in mountains just to the north of Palmyra in central Syria.
"The RAF jets employed Paveway IV guided bombs to target a several entry passages providing entry to the facility... preliminary assessments suggest the strike was effective," the MoD said.
There was no sign of any civilian casualties in the operation conducted Saturday night and each participating jet returned to base without incident, the defence officials confirmed.
The Typhoon FGR4s were backed up by a Voyager tanker plane.
IS - referred to as Daesh - established extremist governance over large swathes of Iraq and Syria prior to its 2019 collapse.
"This operation shows British leadership, and determination to operate in unison with our partners, to eliminate any resurgence of IS and their harmful and extremist ideologies in the region," UK Defence Secretary John Healey said.
RAF aircraft have conducted overwatch operations over Syrian airspace to "prevent any efforts to regroup" of Islamic State subsequent to its defeat at the battle of Baghuz in the year 2019, the authorities noted.
"I extend gratitude to the personnel of our armed forces participating in this operation for their skill and their valour," he added. "They were part of numerous British personnel deployed over the holidays. This mission, to remove dangerous terrorists who pose a risk to our way of life, shows how our armed forces are prepared to act, throughout the year, keeping Britain secure at home and influential overseas."
Last December, the American forces conducted what it described as a "major assault" targeting Daesh sites in Syria, following an attack claimed the lives of two US servicemembers and a civilian interpreter in the Palmyra area.
The UN estimates Islamic State still has between 5,000 and 7,000 fighters in Iraq and Syria.
