A coordinated international police operation has led to the arrest of key members of a criminal network involved in trafficking weapons and drugs across Europe, according to Europol. The action was carried out on 23 March in Spain, Bulgaria and Greece, targeting a group described as operating a “weapons for cannabis” exchange system.

Authorities say the network is believed to have smuggled firearms from Turkey and the Western Balkans into EU territory, where they were exchanged for cannabis and distributed through organized crime channels across several member states. The operation was linked to growing concerns over armed violence in parts of Europe.

Investigators identified a central figure in the organization, a Turkish national with legal residence in Greece, who allegedly coordinated the transport of weapons into Spain while also overseeing drug procurement and distribution routes extending to Greece and Bulgaria.

The investigation began in March 2025 after Spanish police from the Mossos d’Esquadra detected illegal imports of firearms from Turkey, which were being supplied to criminal groups in Catalonia. This discovery led to the identification of a broader network involved in importing, storing and distributing weapons across borders.

Officials described a structured supply chain in which weapons were sourced from the Western Balkans and Turkey, concealed in vehicles with hidden compartments, and transported into the European Union. Once inside the bloc, the firearms were circulated among criminal groups and used as currency in drug transactions.

The group also trafficked so-called “Frankenstein” weapons, assembled from original components combined with improvised metal parts. These low-cost but functional firearms are difficult to trace and have contributed to their widespread use in illicit markets.

Alongside arms trafficking, the organization was heavily involved in large-scale cannabis smuggling. Investigators found that it maintained supply routes for significant quantities of marijuana produced in Catalonia, which were then transported overland and by sea to Greece and Turkey, where prices were higher. The network was capable of moving up to 1.5 tons of cannabis per month.

During the operation, authorities seized around 550 kilograms of cannabis, as well as firearms, ammunition, 76 kilograms of hashish, and additional weapons including seven semi-automatic pistols, a military-grade firearm, and silencers. The estimated street value of the seized drugs was around €4.4 million.

On the day of the coordinated action, Spanish police arrested 18 suspects in multiple locations including Teja, Barcelona, Mataró, Sabadell, Tordera, Lloret de Mar, and Málaga. Bulgarian authorities detained three individuals in Sofia, including the alleged leader of the group, while Greek forces supported operational activities. In total, 21 arrests were carried out.

Europol stated that it played a central role throughout the investigation by supporting intelligence exchange and coordination between national agencies. It assisted in analyzing trafficking routes, mapping the structure of the organization, and linking separate national investigations into a single operational picture.

The agency also facilitated database cross-checks that helped confirm key connections within the network and organised coordination meetings between Spanish, Greek and Bulgarian authorities. According to officials, secure communication channels managed by Europol were essential in building the cross-border intelligence framework that led to the arrests.

Bulgarian officers from the Directorate General for Combating Organized Crime also took part in the operation, contributing to the joint international effort to dismantle the network.