Royal Air Force Typhoon fighter aircraft have conducted a mission with French warplanes in a combined operation targeting an underground arms cache in Syrian territory operated by the IS group, according to the British defence ministry.
The site, located using intelligence, was believed to be storing arms and explosives, the release indicated, and was located in mountainous terrain just north of Palmyra in Syria's central region.
"The RAF jets employed Paveway IV guided bombs to target a number of approach shafts down to the depot... initial indications suggest the objective was successfully hit," the MoD said.
There was no sign of any civilian impact in the strike on Saturday evening and every plane involved made a safe return, the MoD added.
The British jets were backed up by a Voyager tanker plane.
The Islamic State group - also known as ISIS - enforced militant control over significant areas in Iraq and Syria before its territorial defeat in 2019.
"This strike underscores British leadership, and commitment to work closely with our partners, to eliminate any re-emergence of the terrorist group and their dangerous and violent ideologies in the Middle East," the British Defence Secretary John Healey remarked.
RAF aircraft have conducted surveillance missions over Syria to "prevent any attempted resurgence" of IS subsequent to its military defeat at the battle of Baghuz in 2019, the ministry said.
"I must thank the personnel of the UK armed forces involved in this strike for their skill and their valour," he commented. "Including them were a great many British troops on duty over the festive period. This action, to eliminate terrorist threats who endanger our safety, shows how our armed forces are always on standby, continuously, ensuring Britain's security within its borders and influential overseas."
In December, the American forces executed what it described as a "massive strike" on Islamic State objectives in Syria, following an ambush killed two American soldiers and a civilian interpreter in Palmyra.
The United Nations estimates Islamic State still maintains roughly 5-7 thousand militants in Iraq and Syria.