Twenty-one of the suspects were taken to prison and three were put under house arrest. Three other suspects were banned from holding public office, police said.
The arrests were made in the provinces of Milan, Monza and Brianza, Como and Pavia in Lombardy and in Reggio Calabria on the orders of anti-mafia magistrates in Milan and Monza, according to police.
The suspects face charges of mafia association, drug trafficking, extortion, possessing and carrying illegal arms, bodily harm, criminal damage, corrupting public officials, abuse of office and aiding and abetting.
Tuesday's arrests followed a probe begun in 2015 that identified the command structures of the 'Ndrangheta's local branches in the provinces of Monza and Brianza and a gang made up of clans based in the Como area which trafficked "huge" quantities of cocaine investigators said.
The cocaine trafficking racket was operated by individuals with links to powerful 'Ndrangheta clans in the Calabrian town of San Luca, considered the crime organisation's bastion, according to investigators.
The anti-mafia probe also identified a builder in the Lombardy town of Seregno with high-level political contacts as well as links to the 'Ndrangheta, with whom he exchanged favours, said investigators.
The businessman played a key role in the election of Seregno's current centre-right Mayor, Edoardo Mazza, in return for a permit for his company to build a supermarket in the town, investigators allege.
Mazza was put under house arrest on Tuesday on charges of corruption and abetting the unnamed builder with alleged 'Ndrangheta-links.
It was not immediately clear if he was arrested in a separate operation or was among the 24 suspects held in Tuesday's 'Ndrangheta bust.
Drug trafficking, extortion and money-laundering rackets have in the past few decades made the 'Ndrangheta Italy's wealthiest and most powerful international crime syndicate.
The 'Ndrangheta operates throughout Italy and overseas and its influence and networks extend from northern Europe to Australia and North and South America, where it has links to the main drugs cartels.
Investigators have seized hundreds of millions of euros of suspected 'Ndrangheta assets in recent years in an ongoing crackdown.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
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