A statement from the police in Banja Luka said arrests and raids throughout Bosnia started early Monday morning under the monitoring of the State Prosecutor’s office, and that similar operations are being carried out in Serbia, Croatia, Montenegro and Albania.

Because the operation is still ongoing, police could not say how many people were arrested and what has been confiscated.

Countries of the former Yugoslavia had porous borders because of the lack of a solid control system after the wars in the 1990s. Criminals have used this to develop smuggling routes which are now being dealt with as the police organization improves.