British and French fighter jets carried out a joint airstrike in central Syria targeting an underground facility believed to have been used by the Islamic State to store weapons and explosives, the UK Ministry of Defence said Sunday.

According to the ministry, the strike took place Saturday evening in mountainous terrain north of the historic city of Palmyra, in Syria’s Homs province. Britain and France are members of the U.S.-led coalition that has been combating Islamic State militants for more than a decade.

The British military deployed Typhoon FGR4 fighter jets supported by a Voyager aerial refueling tanker, while French aircraft also participated in the operation. The ministry said British forces used Paveway IV precision-guided bombs to strike multiple access tunnels leading to the underground site.

While a full damage assessment is still underway, initial indications suggest the target was successfully hit, the ministry said.

“This action demonstrates the United Kingdom’s leadership and our determination to stand shoulder to shoulder with our allies to prevent any resurgence of Islamic State and its violent ideology in the Middle East,” British Defense Secretary John Healey said in a statement.

There was no immediate response from Syria’s government, which formally joined the international coalition against Islamic State late last year.

Although the group was territorially defeated in Syria in 2019, Islamic State sleeper cells continue to conduct attacks in both Syria and Iraq, where the group once declared a so-called caliphate. United Nations experts estimate the organization still has between 5,000 and 7,000 fighters operating across the two countries.

The strike follows renewed military action in the region. Last month, the Trump administration authorized U.S. strikes in Syria aimed at dismantling Islamic State fighters and weapons sites after an ambush near Palmyra killed two U.S. troops and an American civilian interpreter.

Coalition officials say the latest operation underscores ongoing efforts to prevent the militant group from regrouping and reestablishing a foothold in the region.