British Air Force Typhoon jets have operated alongside French warplanes in a coordinated attack on an underground arms cache in Syria operated by the IS group, according to the UK's MoD.
The facility, pinpointed through reconnaissance, was believed to be storing arms and explosives, the statement said, and was positioned in mountainous terrain just above the ancient city of Palmyra in central Syria.
"The RAF jets employed laser-guided Paveway IV weapons to target a series of access tunnels providing entry to the site... early reports are that the target was engaged successfully," officials stated.
There was no evidence of any harm to civilians in the strike conducted Saturday night and all the aircraft returned to base without incident, the defence officials confirmed.
The British jets were backed up by a Voyager refuelling tanker.
IS - also known as ISIS - established extremist governance over parts of Iraq and Syria until 2019.
"This operation shows the UK's leading role, and resolve to work closely with our partners, to eradicate any revival of the terrorist group and their harmful and extremist ideologies in the Middle East," Britain's Defence Chief the minister remarked.
British military aircraft have conducted overwatch operations over Syria to "forestall any attempted resurgence" of Islamic State following its military defeat at the battle of Baghuz in 2019, the ministry said.
"I extend gratitude to all the members of British forces who took part in this mission for their skill and their courage," Healey said. "They were among thousands of UK service members stationed over Christmas and New Year. This action, to remove militants who endanger our security, shows how our armed forces are always on standby, continuously, ensuring Britain's security domestically and influential overseas."
Last December, the American forces carried out what it called a "massive strike" against Daesh sites in the country, after an attack killed two US troops and a civilian interpreter in Palmyra.
The U.N. says IS still boasts between 5,000 and 7,000 militants in Iraq and Syria.
