Italian authorities have carried out about 170 arrest warrants in a major crackdown on the 'ndrangheta, an organised crime syndicate in southern Italy which officials say has become deeply rooted in the business world in the north.

Italy's chief anti-mafia prosecutor Franco Roberti described the move as a "historic" step in the fight against the mob, during a news conference in Bologna.

Some of those named in the warrants were arrested while others are already incarcerated on other charges or in the process of being detained.

Bologna prosecutor Roberto Alfonso said the operation showed a new side of the 'ndrangheta, which has already infiltrated northern Italy's economic and political networks.

The bulk of the arrest warrants were executed in Emilia Romagna, one of Italy's wealthiest regions.