At least four Jordanian policemen were reportedly killed during clashes with ultra-hardline militants during a raid on a village near the southern city of Karak, a security source said.

Interior Minister Salamah Hamad said on Monday at least five suicide belts were found, together with an ammunition cache, automatic weapons and explosives in a hideout in a house in the desert town of Qatranah, 30 km northeast of Karak.

The clashes had erupted earlier in a village north of the city of Karak, where two days earlier four gunmen killed 10 people in a shootout.

ISIS militants had already claimed responsibility for the shootout at a Crusader castle in Karak in which at least nine people including a Canadian tourist were killed.

An ISIS statement said four of its radical fighters undertook the operation on Sunday that ended in their deaths. Jordanian officials have not said who they suspect in the attack though security sources said the perpetrators were Jordanian nationals.

Jordanian police said late on Sunday that they had killed four “terrorist outlaws” after flushing them out of the castle where they were holed up after an exchange of fire that lasted several hours. Security forces were able to release around 10 tourists unharmed. At least 30 people were taken to hospital.

The gunmen had fled to Karak after an exchange of fire with the police, Hamad said. Based on the quantities of explosives and weapons, “I don’t think the target was just Karak castle, it’s more,” he added. He would not elaborate, saying disclosing details at this stage could imperil national security.

Last November three U.S. military trainers were shot dead when their car was fired on by a Jordanian army member at the gate of a military base. Washington disputed the official Jordanian version that they were shot at for failing to stop, and said it did not rule out political motives.