Rome (AFP) - Italy has thwarted a mobster plan to assassinate the country's interior minister, arresting six Mafia bosses in the Sicilian town of Corleone, police said Friday.

The six are close allies of ruthless Mafia king Salvatore "Toto" Riina, who is currently serving multiple life sentences for murder under Italy's ultra-hard Article 41-bis prison regime, which isolates inmates completely.

Wiretapped conversations between the six had revealed a plot to murder Interior Minister Angelino Alfano because they blamed him for strengthening Article 41-bis, a representative of the regional police force said.

The six were arrested after an investigation begun in September 2014 which revealed not only the assassination bid but also deep divisions within the organised crime group, where Riina's wife Ninetta now calls the shots.

The wiretaps were taken a few months ago and the plan appeared to have been dropped, but police heard chatter between the men over the past few weeks about hiding firearms, sparking the arrests.

Investigators were due to hold a press conference later Friday with more details on the swoop.

Media reports said the six, who lived a rural life on farms in the area of Sicily made famous by the Godfather films, had been plotting to kill Alfano during an electoral rally in the southern Italian region.

"They said they wanted him to meet the same fate as John Fitzgerald Kennedy," the US president assassinated in an open-top car in Dallas in 1963, La Repubblica daily said.

It also emerged from the wiretaps that "the Corleone mobsters believed Cosa Nostra (the Sicilian Mafia) was behind Kennedy's death," the paper added.

The Sicilian Mafia was the country's most powerful organised crime syndicate in the 1980s and 1990s, but has seen its power diminish following years of investigations and mass arrests.

It also faces fierce underworld competition from the increasingly powerful Naples-based Camorra and Calabria's 'Ndrangheta.