Police said the breakthrough came with the arrest of Provenzano

A senior prosecutor, Piero Grasso, said all the suspects had been charged with Mafia association and extortion.

The operation, involving around 500 police officers, included the arrests of 13 alleged Mafia family leaders.

Investigators say the arrests follow leads uncovered after the arrest in April of former Mafia boss Bernardo Provenzano, after 40 years on the run.

Some of the evidence also involved numerous secretly recorded conversations between alleged Mafia bosses, the investigators said.

Mr Grasso declared after the arrests: "Cosa Nostra is down on its knees."

He said they had uncovered evidence "linking Mafia cells with businessmen and politicians", including candidates in recent elections.

Among the key suspects arrested on Tuesday was Antonino Cina, believed to have been the doctor of the previous boss, Salvatore Riina, who was arrested in 1993.

Another was Antonino Rotolo, who was under house arrest but regularly met key Mafia figures and was believed to direct many of the Cosa Nostra's activities in Palermo.

Mr Provenzano had presided over a period of relative calm but, with his arrest, competing bosses are now fighting to take over, the BBC's Christian Fraser reports from Rome.

According to police, the crackdown has averted a potential Mafia turf war.

Some conversations they recorded revealed that mobsters were planning to murder their key rivals.

This is an unprecedented success for Mafia investigators and has undoubtedly dealt a severe blow to the Cosa Nostra's operations, our correspondent says.