Royal Air Force Typhoon FGR4s have joined forces with France's air force in a coordinated attack on an underground arms cache in Syria operated by the IS group, according to the UK's MoD.
The location, pinpointed through intelligence, was thought to be housing weapons and explosive materials, the release indicated, and was located in hills just north of the ancient city of Palmyra in the heart of Syria.
"Our fighter planes used precision-guided Paveway IV munitions to strike a several entry passages down to the depot... early reports are that the strike was effective," the ministry announced.
There was no evidence of any civilian impact in the attack on Saturday evening and every plane involved returned to base without incident, the MoD added.
The Typhoon fighters were assisted by a Voyager aerial refuelling aircraft.
The Islamic State group - also known as the so-called Islamic State - enforced extremist governance over large swathes of both Syria and Iraq before its territorial defeat in 2019.
"This strike shows the UK's leading role, and determination to operate in unison with our allies, to eliminate any resurgence of the terrorist group and their dangerous and violent ideologies in the region," Britain's Defence Chief the Defence Secretary stated.
British military aircraft have conducted overwatch operations over Syrian airspace to "deter any attempted resurgence" of the group following its defeat at the climactic battle in Baghuz in 2019, the ministry said.
"I must thank the personnel of our armed forces who took part in this operation for their expertise and their valour," he added. "Including them were a great many UK service members deployed over the festive period. This operation, to remove terrorist threats who threaten our way of life, demonstrates how UK forces are prepared to act, continuously, protecting the UK domestically and powerful internationally."
In December, the American forces carried out what it described as a "massive strike" against Islamic State objectives in the country, subsequent to an attack killed two US servicemembers and a civilian linguist in the Palmyra area.
The UN reports IS still boasts between 5,000 and 7,000 militants in both countries.
