RAF Typhoon fighter aircraft have joined forces with French aircraft in a coordinated attack targeting an subterranean weapons facility in Syrian territory operated by the IS group, according to the UK's MoD.
The location, located using reconnaissance, was thought to be housing weapons and explosive materials, the statement said, and was situated in mountains just north of the ancient city of Palmyra in the heart of Syria.
"The RAF jets utilized Paveway IV guided bombs to hit a series of entry passages providing entry to the facility... initial indications are that the objective was successfully hit," the MoD said.
There was no indication of any civilian impact in the operation conducted Saturday night and each participating jet returned safely, the ministry further stated.
The Typhoon fighters were backed up by a Voyager refuelling tanker.
Daesh - also known as the so-called Islamic State - enforced jihadist rule over significant areas in both Syria and Iraq until 2019.
"This action demonstrates the UK's leading role, and determination to operate in unison with our partners, to stamp out any resurgence of IS and their harmful and extremist ideologies in the Middle East," UK Defence Secretary John Healey said.
UK warplanes have conducted patrols over Syrian airspace to "prevent any attempted comeback" of the group subsequent to its routing at the battle of Baghuz in 2019, the MoD reported.
"I must thank the personnel of our armed forces who took part in this mission for their expertise and their bravery," Healey added. "Including them were a great many UK service members stationed over Christmas and New Year. This action, to eliminate terrorist threats who pose a risk to our security, highlights how our armed forces are always on standby, all year round, keeping Britain secure within its borders and influential overseas."
In December, the US military executed what it termed a "major assault" on IS targets in the country, after an assault killed two American soldiers and a local interpreter in Palmyra.
The UN reports IS still has an estimated 5,000 to 7,000 combatants in Syria and Iraq.
