The day of arrests on September 17 followed a "large investigation involving law enforcement and judicial authorities from Bosnia and Herzegovina, Croatia and Slovenia," stated a press release from Europol on September 19.

The investigation "has led to the dismantling of a criminal network smuggling migrants from Bosnia and Herzegovina, on to Croatia and then along the so-called Balkan route to Western European countries."

The alleged leader of the criminal network, as well as three other suspects, were arrested in Croatia after nine different locations were searched. Officials also seized electronic equipment and "small amounts of drugs," according to Europol.

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Long investigation

The investigation took place under the umbrella of a dedicated Operational Taskforce, established to provide a coordinated response to smuggling networks.

To date, stated the press release, "authorities have linked the network to more than 100 smuggling incidents involving over 600 migrants." The group is alleged to have "carefully structured its operations," and deployed encrypted communications methods to try and avoid police detection.

The network of criminals, says Europol, "was predominantly composed of Croatian organizers" who then recruited drivers from the Czech Republic, Slovakia, and other Central and Eastern European countries.

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Flights from Istanbul to Sarajevo

In most cases, migrants would enter across the border in Bosnia and Herzegovina after flying in from Istanbul to Sarajevo. After a short stay in Bosnia, the network would then transport migrants to the Bosnian-Croatian border, where they would cross on foot, assisted by guides.

Once in Croatia, it is believed that the gang would arrange temporary accommodation, particularly in the Split area, before driving them on in rented vehicles to other countries.

According to Europol, the "Western Balkans remains a key transit region for secondary movements, where criminal networks actively offer their services to irregular migrants."

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Route into Europe

Europol’s latest Serious and Organized Crime Threat Assessment (SOCTA), published in March 2025, identified the Western Balkan route as one of two primary migration corridors into the European Union.

Criminal networks, stated the report, have developed sophisticated methods to facilitate migrant movements along this route, either by guiding migrants across borders or by providing remote instructions.

Irregular migrants are transported in a variety of passenger and commercial vehicles, often hidden in fuel tanks, between truck compartments or among goods.

"These networks benefit from pre-existing criminal connections, extensive knowledge of the local terrain, and corruption within law enforcement agencies," stated a report published in May this year by the Global Initiative Against Transnational Organized Crime.

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