RAF Typhoon fighter aircraft have operated alongside France's air force in a combined operation on an underground arms cache in Syria operated by the Daesh militant organization, according to the British defence ministry.
The facility, located using surveillance, was believed to be housing weapons and explosive materials, the statement said, and was situated in hills just above Palmyra in the heart of Syria.
"The RAF jets employed precision-guided Paveway IV munitions to hit a number of entry passages down to the depot... early reports suggest the target was engaged successfully," the MoD said.
There was no sign of any civilian casualties in the operation on Saturday evening and each participating jet made a safe return, the MoD added.
The Typhoon fighters were assisted by a Voyager aerial refuelling aircraft.
The Islamic State group - alternatively referred to as ISIS - enforced militant control over large swathes of Syria and Iraq until 2019.
"This strike shows our UK leadership, and resolve to operate in unison with our allies, to eliminate any re-emergence of IS and their violent and radical beliefs in the Middle East," the British Defence Secretary John Healey remarked.
UK warplanes have performed patrols over Syrian airspace to "forestall any attempted comeback" of the group following its military defeat at the battle of Baghuz in the year 2019, the authorities noted.
"I must thank all the members of the UK armed forces who took part in this operation for their professionalism and their valour," the Defence Secretary added. "They were part of numerous UK service members deployed over Christmas and New Year. This operation, to remove dangerous terrorists who endanger our security, demonstrates how UK forces are always on standby, throughout the year, ensuring Britain's security domestically and strong abroad."
During December, the US military carried out what it termed a "major assault" targeting Daesh sites in Syria, following an assault claimed the lives of two American soldiers and a civilian interpreter in Palmyra.
The U.N. estimates IS still has an estimated 5,000 to 7,000 militants in both countries.
