Facebook and Instagram on Monday blocked the social media accounts of two Italian neo-fascist groups and some of their activists because they had violated the platforms' policies against spreading hate, Facebook said.
Casapound and Forza Nuova, which espouse extreme right-wing ideologies, have boosted their profile in Italy by leading anti-migrant campaigns on their social media sites.
"People and organisations that spread hatred or attack others based on who they are, have no place on Facebook and Instagram," Facebook, which owns Instagram, said in a statement.
Casapound leader Simone Di Stefano denounced the decision.
"This is an abuse by a private multinational in contempt of Italian law. A spit in the face of democracy," he wrote in a tweet. Casapound had 250,000 followers on Facebook.
Di Stefano said his personal profile, which had 140,000 followers, had been shuttered along with those of a number of city councillors around Italy who belong to the group.
Forza Nuova leader Roberto Fiore confirmed his movement's profiles had also gone dark, and said his group would respond with more street protests and recruitment.
The groups' political opponents applauded the move.
"This is another step towards the end of an organised season of hatred on social networks," said former lower house speaker and left-wing lawmaker Laura Boldrini.
On Monday, Casapound and Forza Nuova supporters took part in a protest outside parliament to demand snap elections after the centre-left Democratic Party replaced the far-right League in a coalition with the anti-establishment 5-Star Movement.
Some of those in the crowd were filmed making the stiff-armed fascist salute.
