Croatian police said on Thursday that they arrested three men in an investigation of a suspected five-person illegal arms smuggling ring. The suspects are thought to have ordered hand guns and weapon parts online from the United States, which were then delivered to Croatia in parcels with false declarations, to be sold on the local black market.

The suspects are four Croatian nationals aged 34 and 63, and a 31-year-old man holding dual Croatian and Dutch citizenship, the Interior Ministry said.

The Uskok anti-corruption police said that the five suspects were subjects of a police investigation on suspicion of unlawful possession, production, and the procurement of weapons, with the intention of sale.

Postal shipments with handguns or their parts from the US were falsely declared as car and motorcycle parts or toys, and the group included a postal customs official who took care that the shipments avoided customs control when entering the country.

The Interior Ministry said that three of the five suspects have been placed in custody over the charges, and another one has already been detained on separate charges of holding large quantities of arms and ammunition in his home, as well as large quantities of cash. The fifth suspect, a 31-year-old man, is currently at large.

The Interior Ministry said that during its investigation it closely cooperated with law enforcement agencies of the United States and the United Kingdom, as well as with the Croatian customs service, and the Croatian Post.