Royal Air Force Typhoon fighter aircraft have operated alongside French aircraft in a joint strike on an underground arms cache in Syrian territory employed by the IS group, according to the UK Ministry of Defence.
The location, identified by surveillance, was assessed as housing weapons and explosive materials, the release indicated, and was situated in hills just north of Palmyra in the heart of Syria.
"Our fighter planes employed Paveway IV guided bombs to hit a number of entry passages providing entry to the depot... preliminary assessments are that the strike was effective," the MoD said.
There was no sign of any civilian casualties in the attack on Saturday evening and every plane involved returned to base without incident, the MoD added.
The British jets were assisted by a Voyager aerial refuelling aircraft.
The Islamic State group - alternatively referred to as the so-called Islamic State - enforced militant control over parts of Iraq and Syria before its territorial defeat in 2019.
"This operation shows our UK leadership, and commitment to operate in unison with allied nations, to stamp out any re-emergence of Daesh and their harmful and extremist ideologies in the area," the British Defence Secretary John Healey said.
RAF aircraft have carried out overwatch operations over Syrian airspace to "deter any efforts to regroup" of the group after its routing at the Baghuz confrontation in 2019, the MoD reported.
"I want to thank the personnel of British forces who took part in this operation for their expertise and their courage," Healey commented. "They were among numerous British personnel deployed over the festive period. This mission, to take out terrorist threats who threaten our safety, demonstrates how UK forces are ready to step up, all year round, ensuring Britain's security within its borders and influential overseas."
Last December, the American forces carried out what it called a "large-scale strike" on Islamic State objectives in Syria, after an ambush claimed the lives of two US servicemembers and a civilian linguist in the Palmyra area.
The United Nations says IS still has an estimated 5,000 to 7,000 fighters in both countries.
