Royal Air Force Typhoon jets joined French aircraft in a joint air strike on an underground arms cache in Syria that was believed to have been used by the Islamic State group to store weapons and explosives.

The facility had been identified through intelligence and was located in mountainous terrain just north of Palmyra, the ancient site in central Syria.

Officials said the attack focused on access tunnels leading down to the underground complex.

According to the official account of the operation, the aircraft used Paveway IV precision-guided bombs to hit multiple tunnel entrances.

Initial indications were described as consistent with a successful engagement of the target, while a fuller assessment continued.

The strike took place late on Saturday.

Officials said there was no sign of harm to civilians, and all aircraft returned safely.

The mission included support from a Voyager air-to-air refuelling tanker.

The Islamic State group, also known as Daesh, once imposed jihadist rule over large parts of Syria and Iraq before losing its territorial control in two thousand nineteen.

Officials said ongoing patrols and targeted action are intended to prevent any attempted resurgence following the group’s defeat at the battle of Baghuz in two thousand nineteen.

Separately, it was noted that in December the United States military carried out what it described as a massive strike against Islamic State targets in Syria after an ambush in the Palmyra area killed two American soldiers and a civilian interpreter.

The United Nations has said Islamic State still has between five thousand and seven thousand fighters across Syria and Iraq.

The operation underscored the continued international campaign to deny Islamic State the space, stocks, and sanctuary needed to regroup.