Italian police said on Thursday they uncovered a plot to form a new Nazi party and seized a cache of weapons during searches across the country.

Police in 16 towns and cities from the Mediterranean island of Sicily to the Alps in northern Italy took part in the investigation, which was launched two years ago.

The probe revealed a "huge and varied array of subjects, residents in different places, united by the same ideological fanaticism and willing to create an openly pro-Nazi, xenophobic and anti-Semitic movement", a police statement said.

Police did not say how many people joined the group or how many arrests were made. In Italy "defence of fascism" and efforts to revive fascist parties are crimes.

The new party was called the Italian National Socialist Party of Workers and police showed off a range of Nazi paraphernalia, including swastikas and pictures of Adolf Hitler seized during searches of 19 properties.

Open gallery view Automatic weapons, rifles, crossbows, swords, knives and Nazi books and flags found during a search at the homes of 19 suspects throughout Italy, November 28, 2019. Credit: AFP

They also found a large number of weapons, including pistols, hunting rifles and crossbows.

The group had forged links with extremist groups abroad, including in Portugal, Britain and France, police said.

Police in July found a huge stash of weapons, including an air-to-air missile, linked to far-right extremists, while in November two men connected to another group of Nazi sympathisers were arrested on suspicion of planning to attack a mosque.