Virtually the entire leadership of the Detroit mafia was indicted by a federal grand jury on 25 different charges, Attorney General Janet Reno announced Thursday.

"Arrests began last night to take out the entire leadership of the Detroit La Cosa Nostra," Reno told her weekly news conference. "Nine of the 17 defendants are accused of committing over a 30-year period numerous acts of violence, extortion and racketeering."The conduct includes infiltration of several Las Vegas casinos, plotting murders and beatings and corrupting officials. Other defendants are accused of a variety of illegal acts," she said.

Four of the defendants were arrested Wednesday at vacation homes in West Palm Beach, Fla., Justice Department spokesman John Russell said.

Rick Mosquera, chief of the FBI's organized crime section, said nine of the 17 defendants were "made members" of the Detroit Mafia family and represented "the historical leadership of this family for the past 30 years."

They included Jack Tocco, whom Reno described as "the lead defendant" and "one of the longest tenured and most powerful LCN bosses in the country."

The Detroit mob made most of its money from extortion, loan-sharking, sports bookmaking and protection rackets, Mosquera said. It relied on collection techniques like "shooting at people and placing bombs in businesses," he added.

The 41-page indictment from a Detroit grand jury said the mob acquired or tried to acquire hidden financial interests in Nevada casinos, including the Frontier and Aladdin in Las Vegas and the Edgewater Hotel and Casino in Laughlin, Nev.