Italian police said Monday they had seized weapons including an air-to-air missile in raids on far-right extremist groups.

Neo-Nazi propaganda was also seized during the raids in several cities against Italians suspected of aiding pro-Russian rebels fighting Ukrainian troops in Donbass.

"During the operation, an air-to-air missile in perfect working order and used by the Qatari army was seized," police said in a statement.

As well as the Matra missile, the raid uncovered a stash of sophisticated weapons, including "latest generation" automatic assault rifles and rocket launchers.

Police arrested three people, including Fabio Del Bergiolo, 50, a former candidate for the neo-fascist Forza Nuova party.

The others were a 42-year-old Swiss and an Italian, 51, arrested near Forli airport on suspicion of trying to sell the missile.

The Digos law enforcement agency, which deals largely with terrorism and organised crime, led the operation from Turin with assistance from police in Forli, Milan, Novara and Varese.

"We have some idea about what the seized equipment could be used for, but will not speculate," Turin police commissioner Giuseppe De Matteis told reporters.

"For now, there is nothing to lead us to suspect" an active plot to use the weapons, said counter-terrorism official Eugenio Spina.

Police have carried out several raids in recent weeks on far-right targets around Turin.

The latest, on 9 July, led to the arrest of Fabio Carlo D'Allia, accused of advocating fascism and harbouring weapons.