Royal Air Force Typhoon jets have joined forces with French warplanes in a combined operation targeting an underground arms cache in Syria operated by the IS group, according to the UK's MoD.
The site, identified by intelligence, was believed to be storing arms and explosives, the release indicated, and was located in mountains just above the ancient city of Palmyra in central Syria.
"The RAF jets utilized laser-guided Paveway IV weapons to hit a series of entry passages providing entry to the site... early reports are that the strike was effective," the ministry announced.
There was no evidence of any civilian impact in the attack late on Saturday and all the aircraft returned to base without incident, the defence officials confirmed.
The Typhoon FGR4s were supported by a Voyager refuelling tanker.
Daesh - also known as ISIS - established jihadist rule over large swathes of Iraq and Syria prior to its 2019 collapse.
"This action demonstrates British leadership, and commitment to stand shoulder to shoulder with allied nations, to eliminate any resurgence of IS and their dangerous and violent ideologies in the area," the British Defence Secretary the minister said.
British military aircraft have carried out overwatch operations over Syrian airspace to "deter any attempted comeback" of Islamic State following its military defeat at the climactic battle in Baghuz in 2019, the MoD reported.
"I must thank the personnel of our armed forces involved in this strike for their expertise and their courage," the Defence Secretary added. "Including them were a great many British personnel on duty over the holidays. This mission, to eliminate terrorist threats who threaten our security, shows how British military are always on standby, throughout the year, keeping Britain secure domestically and influential overseas."
In December, the American forces conducted what it termed a "large-scale strike" against Islamic State objectives in Syria, following an ambush claimed the lives of two American soldiers and a civilian interpreter in the Palmyra area.
The United Nations estimates IS still maintains an estimated 5,000 to 7,000 militants in Syria and Iraq.
