Police in Finland say they've stopped a far-right terror plot that would have used 3D printed weapons in an attack aimed at leading to the "collapse of society" in a race war.

       The National Bureau of Investigation says their initial probe was just looking into a simple firearms offense, but they soon realised there was a bigger issue involving at least four men with links to the far-right.

       Local media reports that one of the men in custody had been a municipal election candidate for the Finns Party, which is one of the four parties which makes up the Nordic nation's coalition government.

       The men are suspected of manufacturing submachine guns using 3D printers, as well as other weapons and printed gun parts, in a rented garage as well as in the home of one of the suspects. Police also confiscated a rifle, a home-made pen pistol, and a gas gun converted into a firearm as well as 3D printers and cannabis plants.

       "According to the police's understanding, the targets of the planned violent attacks were selected as targets based on their skin color, political or other ideological views," says Crime Commissioner Tuomas Kuure, who told reporters the men wanted to ignite a "race war" in Finland.

       "In addition to the personal targets, the suspects have planned attacks on different parts of the infrastructure in their conversations, including the electricity network and rail traffic," he added.

       Police say the men had formed a radicalised group and were specially trained in 3D weapons technology as they "prepared to commit a terrorist act."