Alfano, who is also the interior minister, said the sometimes violent rallies, which are calling for tax cuts to small businesses, is “a violent front that has violated the law”.
He warned that the manifestations could attract “violent groups”.
“While protest is acceptable in a democracy, violence will not be tolerated”, he added.
The protesters are linked to the "Forconi" (Pitchfork) movement, which started in Sicily among farmers incensed by rising taxes.
From farmers the movement spread to craftsmen, store owners and truck drivers, all of whom are increasingly frustrated with reforms demanded by cost-conscious Rome.
On Monday, stone-throwing protestors clashed with police in Turin, in one of dozens of rallies called to demand tax cuts for small businesses.
Police have also fired teargas at demonstrators near Italy’s border with France.
Members of the Fiom metalworkers' union were also expected to take to the streets of Rome to demand more help from the government to save jobs.