British and French warplanes carried out an airstrike in central Syria on an underground facility where members of the Islamic State group are suspected to have stored weapons and explosives, the British defense ministry said Sunday, January 3.

The strikes occurred Saturday evening on the structure in the mountains just north of the historic town of Palmyra in the country’s Homs province, the ministry’s statement said. “This facility had been occupied by Daesh, most likely to store weapons and explosives. The area around the facility is devoid of any civilian habitation,” the statement added.

The ministry said the British military used Typhoon FGR4 fighter jets supported by a Voyager refueling tanker and were joined by French aircraft in the joint strike. The British air force used Paveway IV guided bombs to target a number of access tunnels down to the facility, the statement said, adding that while a detailed assessment is now underway, initial indications are “that the target was engaged successfully.”

“This action shows our UK leadership, and determination to stand shoulder to shoulder with our allies, to stamp out any resurgence” of IS and its “violent ideologies” in the Middle East, said Defense Secretary John Healey.

Britain and France are part of the US-led coalition that has been fighting IS militants for more than a decade. There was no immediate comment from Syria’s government on the strikes. Syria joined the anti-IS coalition late last year.

Despite its defeat in Syria in 2019, IS sleeper cells still carry out deadly attacks in Syria and Iraq where the extremists once declared their caliphate. UN experts say IS still commands between 5,000 and 7,000 members across its former stronghold in Syria and Iraq.

Last month, the Trump administration launched military strikes in Syria to “eliminate” IS fighters and weapons sites in retaliation for an ambush attack near Palmyra that killed two US troops and an American civilian interpreter days earlier.