British Air Force Typhoon fighter aircraft have conducted a mission with French warplanes in a joint strike on an underground arms cache in Syrian territory used by the IS group, according to the UK Ministry of Defence.
The site, identified by surveillance, was thought to be containing munitions and bombs, the statement said, and was positioned in mountains just north of Palmyra in the heart of Syria.
"The RAF jets employed precision-guided Paveway IV munitions to strike a series of entry passages leading to the site... preliminary assessments are that the strike was effective," the MoD said.
There was no evidence of any civilian casualties in the operation on Saturday evening and each participating jet made a safe return, the defence officials confirmed.
The Typhoon fighters were assisted by a Voyager tanker plane.
IS - referred to as Daesh - established extremist governance over significant areas in both Syria and Iraq until 2019.
"This operation underscores the UK's leading role, and resolve to work closely with our partners, to eradicate any revival of IS and their harmful and extremist ideologies in the area," Britain's Defence Chief the minister stated.
UK warplanes have carried out surveillance missions over Syria to "forestall any attempted resurgence" of Islamic State subsequent to its defeat at the climactic battle in Baghuz in the year 2019, the ministry said.
"I must thank all the members of British forces involved in this operation for their expertise and their bravery," he added. "They were part of a great many British personnel on duty over the holidays. This action, to eliminate dangerous terrorists who pose a risk to our way of life, highlights how our armed forces are always on standby, all year round, keeping Britain secure domestically and strong abroad."
Last December, the American forces executed what it called a "major assault" targeting IS targets in the country, after an attack resulted in the deaths of two American soldiers and a civilian interpreter in Palmyra.
The UN says IS still boasts between 5,000 and 7,000 fighters in both countries.
