A recent bomb attack in a court building was the start of a new "Mafia campaign" in Italy, top anti-Mafia prosecutor Piero Grasso warned on Wednesday.

A powerful home-made bomb partially exploded at a courthouse in the southern city of Reggio Calabria on Sunday in a strike blamed on the Calabrian Mafia, which is also known as 'Ndrangheta.

"It's unacceptable that judges are attacked in such a way," Grasso said."The state and government must protect the judiciary, and the judiciary must be united in responding to the Mafia campaign."

The top prosecutor urged the strengthening of national investigation procedures in order to arrest criminals and seize their assets. Grasso has repeatedly called as well for international cooperation and common laws to curb Italian Mafia's worldwide expansion.

According to Grasso, the bombing was the product of political tensions and a crusade of hate launched against the country's judiciary.

Italy's political scene has been recently rocked by a fierce wrestle, with the opposition and the judiciary on one side, and Prime Minister Silvio Berlusconi and his center-right government on the other.

Berlusconi was injured in a political rally on December 11, and several failed bomb attacks occurred in the country just before Christmas, one at a private business university.

According to a number of newspapers, Italy is on the verge of re-living the same era of violence and terrorism experienced 30 years ago, when left and right wing militia bitterly fought each other.

The Mafia in the past has taken advantage of Italy's political instability to pursue its own interests against the country.

Roberto Saviano, internationally acclaimed author of the anti-Mafia best-seller "Gomorra," wrote Tuesday in the La Repubblica daily that a "military campaign" had been launched against Italian institutions and it was just the beginning.

"If they had wanted to do it, the clans could have blown up all of Reggio Calabria," he said. "'Ndrangheta possesses plastic explosives and dozens of rocket launchers."

"Why then did they explode a home-made bomb in front of the prosecutor's office? Obviously they did not want to strike severely but to launch the first signal, to begin a military campaign."

The 30-year-old author lives in hiding under a 24-hour escort due to repeated death threats by the Mafia.