Royal Air Force Typhoon jets have conducted a mission with France's air force in a combined operation against an underground arms cache in Syria operated by the IS group, according to the UK's MoD.
The site, pinpointed through surveillance, was thought to be housing weapons and explosive materials, the statement said, and was situated in mountainous terrain just above Palmyra in the heart of Syria.
"The RAF jets utilized laser-guided Paveway IV weapons to target a number of access tunnels down to the facility... preliminary assessments are that the target was engaged successfully," the MoD said.
There was no evidence of any harm to civilians in the operation late on Saturday and each participating jet returned safely, the ministry further stated.
The Typhoon FGR4s were assisted by a Voyager aerial refuelling aircraft.
Daesh - alternatively referred to as the so-called Islamic State - imposed extremist governance over significant areas in both Syria and Iraq before its territorial defeat in 2019.
"This action underscores the UK's leading role, and commitment to stand shoulder to shoulder with our partners, to stamp out any resurgence of Daesh and their harmful and extremist ideologies in the area," UK Defence Secretary John Healey stated.
UK warplanes have carried out patrols over Syria to "prevent any efforts to regroup" of IS following its defeat at the climactic battle in Baghuz in 2019, the MoD reported.
"I want to thank every member of our armed forces participating in this operation for their professionalism and their valour," the Defence Secretary added. "They were part of a great many British personnel on duty over Christmas and New Year. This action, to take out terrorist threats who endanger our way of life, shows how UK forces are always on standby, throughout the year, keeping Britain secure within its borders and influential overseas."
Last December, the US military conducted what it termed a "major assault" against IS targets in the country, subsequent to an ambush resulted in the deaths of two US servicemembers and a civilian interpreter in the Palmyra area.
The United Nations says Islamic State still has roughly 5-7 thousand combatants in Iraq and Syria.
