Police in Italy say they have arrested 19 far-right extremists who wanted to form a new Nazi party.

In raids across the country, police discovered weapons, explosives, Nazi plaques featuring swastikas, Nazi flags and books on Adolf Hitler and Benito Mussolini.

According to prosecutors in Caltanissetta, Sicily, who have led the investigation named Black Shadows, the suspects allegedly wanted to create “an openly pro-Nazi, xenophobic, antisemitic group called the Italian National Socialist Workers’ Party”.

The members made contact with other neo-Nazi groups outside Italy, including Britain’s Combat 18 and Portugal’s far-right New Social Order.

The head of the organisation was a 50-year-old woman based in Padua, in the north of Italy, who works in the public administration and has no criminal record. According to the police, her nickname was “Hitler’s Sergeant Major”. Investigators found swastikas and antisemitic material at her home.

Another suspect is a 26-year-old woman from Sicily who once won an online beauty contest called “Miss Hitler” and in August spoke at a far-right conference in Lisbon.

The head trainer of the militants was a former senior member of the powerful Calabrian mafia ‘Ndrangheta, who turned supergrass a few years ago and has since collaborated with the police. He was also a former member and contact person in the region of Liguria of the neo-fascist political party Forza Nuova.

In the homes of the suspects, police found leaflets with insults against two MPs for the centre-left Democratic party – Emanuele Fiano, a prominent figure in the Italian Jewish community, and Laura Boldrini, a former parliamentary speaker and a victim of persistent online abuse and bogus news reports.

“If you are trying to scare me, you got it wrong,’’ said Fiano on Facebook. “Not even the real Nazi destroyed us, never mind you.”

Last July police in northern Italy detained three men after uncovering a huge stash of automatic weapons, material featuring Nazi symbols and a three-metre air-to-air missile in a hangar of Rivanazzano Terme airport in Lombardy.