RAF Typhoon FGR4s have conducted a mission with French aircraft in a coordinated attack against an hidden munitions depot in Syria operated by the IS group, according to the UK's MoD.
The site, identified by surveillance, was assessed as storing arms and explosives, the statement said, and was located in mountains just north of the historic site of Palmyra in the heart of Syria.
"The RAF jets utilized Paveway IV guided bombs to strike a several approach shafts leading to the depot... initial indications are that the strike was effective," the ministry announced.
There was no indication of any civilian casualties in the operation late on Saturday and every plane involved returned to base without incident, the defence officials confirmed.
The Typhoon fighters were backed up by a Voyager aerial refuelling aircraft.
The Islamic State group - alternatively referred to as Daesh - enforced militant control over large swathes of both Syria and Iraq before its territorial defeat in 2019.
"This action shows the UK's leading role, and commitment to work closely with our allies, to eliminate any revival of the terrorist group and their dangerous and violent ideologies in the Middle East," the British Defence Secretary John Healey stated.
UK warplanes have carried out patrols over Syrian airspace to "deter any attempted resurgence" of Islamic State following its defeat at the battle of Baghuz in 2019, the authorities noted.
"I extend gratitude to the personnel of our armed forces who took part in this strike for their skill and their valour," Healey commented. "They were among thousands of British troops on duty over the holidays. This action, to eliminate militants who threaten our safety, highlights how our armed forces are always on standby, all year round, ensuring Britain's security within its borders and strong abroad."
Last December, the US military executed what it called a "large-scale strike" against Daesh sites in Syria, after an ambush killed two American soldiers and a local interpreter in the Palmyra area.
The UN says Islamic State still boasts an estimated 5,000 to 7,000 militants in Syria and Iraq.
