Royal Air Force Typhoon jets have operated alongside France's air force in a coordinated attack against an underground arms cache in Syrian territory employed by the IS group, according to the UK's MoD.
The location, identified by surveillance, was thought to be housing weapons and explosive materials, the statement said, and was situated in mountainous terrain just above Palmyra in Syria's central region.
"The RAF jets used precision-guided Paveway IV munitions to target a number of access tunnels providing entry to the site... early reports suggest the target was engaged successfully," officials stated.
There was no evidence 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 assisted by a Voyager tanker plane.
Daesh - also known as the so-called Islamic State - imposed militant control over large swathes of both Syria and Iraq prior to its 2019 collapse.
"This strike shows our UK leadership, and determination to work closely with our allies, to eradicate any re-emergence of Daesh and their harmful and extremist ideologies in the area," Britain's Defence Chief the Defence Secretary remarked.
RAF aircraft have conducted overwatch operations over Syrian airspace to "deter any attempted comeback" of IS following its routing at the climactic battle in Baghuz in 2019, the ministry said.
"I must thank every member of British forces participating in this mission for their professionalism and their valour," the Defence Secretary said. "They were among a great many UK service members on duty over the holidays. This action, to remove militants who endanger our security, shows how UK forces are always on standby, continuously, ensuring Britain's security domestically and influential overseas."
During December, the American forces executed what it termed a "major assault" on Islamic State objectives in the country, after an assault claimed the lives of two US troops and a civilian interpreter in the Palmyra area.
The U.N. estimates Daesh still maintains between 5,000 and 7,000 combatants in Syria and Iraq.
