In a press statement issued on Wednesday, Denmark’s State Police said it worked closely with the Danish Security and Intelligence Service (PET) to arrest the two men, as part of “a long-term investigation” that continues to take place in the Greater Copenhagen area.

According to the press statement, the two men are members of Danish-based Islamist groups and were known to police prior to their arrest this week. They are also believed to be part of a larger network of Islamist activists in the Scandinavian country who support the Islamic State —also known as the Islamic State of Iraq and Syria (ISIS). A police spokesman said on Wednesday that the case involves the “procurement and facilitation” of unmanned aerial vehicle components, “including drones, from Denmark to the Islamic State in Syria and Iraq”. The components were procured with the purpose of being used in reconnaissance and combat operations abroad by the militant group, he added.

This is the second time that Danish authorities have arrested individuals for attempting to procure drones and drone equipment for the Islamic State. A year ago, a 28-year-old man was charged with shipping disassembled drone equipment and infrared cameras to an address in Turkey. The shipped material was collected up by a Turkish couple who were Islamic State members and were arrested following an international police operation. The Islamic State has been using drones [.pdf] since October of 2016, when it deployed a bomb-laden UAV to kill two Kurdish soldiers. In January of last year, the militant group aired propaganda footage showing several cases of dropping bombs on adversary troops and civilians using specially modified drones.

The two men arrested this week are expected to appear in court on Thursday. It is believed that state prosecutors will request a closed-door hearing, since the investigation against the network of ISIS supporters in Denmark is ongoing.