Police in Serbia and Slovenia have arrested six people and are searching for two more in a suspected drug-smuggling operation that allegedly used companies to move narcotics across Europe. The suspects allegedly opened transport firms and registered trucks for international road haulage, then hid drugs inside secret compartments built into the vehicles. Authorities say the alleged scheme operated across Croatia, Hungary, Slovakia and Serbia, with further evidence linked to arrests in France. According to Serbian police, three people were arrested in Serbia, aged 23 to 54, over suspicions they produced and sold drugs. Slovenian police arrested one man each who is Serbian, Slovenian and Bosnian, aged 34 to 44, as part of the same organised group. Two other people are still being sought. Investigators allege that the trucks used by the group carried legitimate cargo, while bunkers were installed separately inside the cabins to conceal drugs during transport. The operation relied on the transport companies as cover for the illegal shipments. Serbian police also point to a related case from the second half of 2025, when two drivers were arrested in France over suspicions they smuggled drugs for the group using trucks carrying cargo moving from Spain. The investigation is ongoing as searches continue for the two unapprehended suspects.