MILAN (AP) — A court in Italy convicted a mob boss, three police investigators and a close associate of former Premier Silvio Berlusconi in a case showing collusion between the Sicilian Mafia and state institutions after a deadly wave of mafia bombings during the early 1990s.

Prosecutor Nino Di Matteo said the long-awaited verdicts demonstrated with "certainty that while in Italy bombs were exploding, in 1992 and 1993, some representatives of the government were negotiating with the Cosa Nostra and transmitting threats of the Cosa Nostra to the government."

During the course of the 5-year trial, two top defendants among the eight charged died while serving multiple life sentences: Mafia bosses Bernardo Provenzano and Salvatore "Toto" Riina. More than 200 people testified during more than 200 hearings.

Mafia boss Leoluca Bagarella received the toughest sentence, 28 years, while former Forza Italia Senator Marcello Dell'Utri, already jailed for acting as a go-between between the Mafia and Berlusconi, was sentenced to 12 years.

Two carabinieri investigators also were given 12 years, while a third police investigator received an eight-year sentence. Former Interior Minister Nicola Mancino was acquitted of false testimony.

The verdicts come a quarter century after the mafia bombings in Florence, Milan and Rome, as well as the assassinations of anti-mafia prosecutors Giovanni Falcone and Paolo Borsellino and their security details.

The eight people the court in Palermo convicted Friday were accused of trying to be a bridge between the Sicilian mob bosses who masterminded the bombings and government officials, with the aim of ending harsh anti-Mafia laws.

Di Matteo said Dell'Utri's conviction made clear that he had transmitted requests between the Mafia and Berlusconi's first government, which began in 1994.

"The relationship didn't stop with Berlusconi, the entrepreneur, but arrived at Berlusconi, the politician," he said.

The verdicts came as talks on forming a new Italian government remain stalled. They only hardened the resolve of the 5-Star Movement leader to not have anything to do with Berlusconi, who is part of the center-right coalition that won 37 percent of the votes in last month's election to the 5-Stars' 32 percent.

Five-Star leader Luigi Di Maio said in a tweet that the verdicts demonstrated that "there were Mafia-state negotiations." Referring to the two decades Berlusconi dominated Italy's politics, he added: "The Second Republic dies definitively with these convictions."

In a statement, Berlusconi denied ever having anything to do with the Mafia and said his governments fought against organized crime.

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