Updated

Italian police staged sweeping raids Tuesday to arrest about 90 suspected mobsters and prevent the hobbled Sicilian Mafia from forming a new command structure and strategy, authorities said.

The blitz ordered by Palermo prosecutors was one of the largest in recent years and was billed as striking at the heart of the nascent hierarchy. It prevented possible bloodshed among bosses competing for control in a new ruling commission, police said.

"The operation has thrown the Mafia into a very serious crisis," said Francesco Messineo, the chief prosecutor in Palermo who ordered the arrests.

The Sicilian Mafia has been trying to overcome disarray in its ranks ever since top mobster Bernardo Provenzano was arrested in April 2006. Many of his encrypted notes were cracked, shedding light on Cosa Nostra's organization and leading to the arrests of some of his closest aides.

"If that operation ... brought Cosa Nostra down to its knees, this prevented it from getting up again," said the national anti-Mafia prosecutor, Pietro Grasso.

Tuesday's operation — called Perseus, after the Greek mythological hero who beheaded Medusa — "severed all the strategically important heads of a new ruling structure that had to deliberate, as it once did, on all serious acts," Grasso said.

The arrests targeted 89 suspected bosses of local crime families and rank-and-file mobsters intent on setting up the commission, which was to make Cosa Nostra's important decisions including possible attacks, police said.

Some suspects remained at large.

The commission, known as the "cupola," was famously headed by Salvatore "Toto" Riina, the boss of bosses, until his arrest in 1993. Under Riina's command, the commission adopted a strategy of all-out attack against the state that culminated with the back-to-back slayings of top anti-Mafia fighters Giovanni Falcone and Paolo Borsellino in 1992.

Provenzano, who took over from Riina, pursued a less bloody strategy and focused on the Mafia's traditional illegal activities, such as infiltrating public projects or extortion from local businesses.

By contrast, organized crime syndicates active elsewhere in Italy gained the spotlight: The Neapolitan Camorra became the subject of the best-seller "Gomorrah," now an award-winning film; and the 'ndrangheta, based in the southern region of Calabria, made headlines with the 2007 movie-style killing of six Italians outside a pizza restaurant in Germany.

The raids Tuesday involved 1,200 police officers, helicopters and dog units. Footage provided by the Carabinieri to Italian TV showed cars and police officers besieging homes, masked officers climbing gates and tearing down walls, while helicopters hovered above.

Hours later, dozens of handcuffed suspects, some of them grinning defiantly, were shown being escorted out of a police station in Palermo and taken to prison. They are charged with Mafia association, extortion, arms and drug trafficking, the Carabinieri said in a statement.

Months of wiretapping gave investigators a clear picture of the highest echelons of the Mafia. "We had the opportunity to hear Cosa Nostra's voice in real time for nine months," said Messineo.

The attempt to restore the commission was masterminded by a suspected mobster, Matteo Messina Denaro, who is among a handful of people vying to replace Provenzano, police said.

Messina Denaro is seen by investigators as a top candidate for the job after his main competitors were arrested. He remains at large.

"The operation must be seen in the context of an ongoing offensive against the Mafia, and in that respect it deals a serious blow," said Umberto Santino, the founder and president of a research center into Mafia history and activities in Palermo.