Federal authorities broadened their nationwide crackdown on organized crime Monday, arresting the reputed leaders of Philadelphia’s La Cosa Nostra family on extortion, loan-sharking and other charges.

The indictment of 13 members and associates of the Philadelphia family is the latest in a series of high-profile roundups of alleged East Coast mafia members this year. Federal officials say the scope and severity of the charges show that the mafia remains a resilient foe, even after a decades-long FBI campaign against it.

In the newest case, authorities unsealed an indictment charging alleged Philadelphia boss Joseph Ligambi and 12 other mafia members and associates with criminal conduct that included racketeering conspiracy and illegal gambling. Federal officials said the defendants infused their activities with violence, using phrases such as “chop him up” and “put a bullet in your head” when threatening victims.

“This department has shown that our commitment to fighting organized crime is backed by actions,’’ Lanny A. Breuer, assistant attorney general for the Justice Department’s Criminal Division, said at a news conference in Philadelphia. “Arrests, charges, convictions, prison sentences — the drumbeat of enforcement is growing louder, and organized crime figures throughout the country should hear it and take notice.”

The mass arrests of reputed organized crime figures, an increasingly common tactic in recent years, tend to recall images from mafia movies that have lingered in the popular imagination. Authorities said one of the defendants, Damion Canalichio, used a bat to beat a victim for not paying a loan debt — a tactic reminiscent of a famous and gory scene involving Al Capone’s character in “The Untouchables.’’

But federal officials emphasized the real-life threat posed by organized crime families who have little regard for the law.

“The life of a traditional ‘mobster’ has been dramatized in the movies and on TV,” Breuer said. “But there is nothing entertaining about violence in our communities.”

It was unclear whether attorneys had been appointed for the defendants, who included another alleged member of the Philadelphia family’s ruling hierarchy, underboss Joseph Massimino. FBI agents and local officers arrested 11 of the defendants Monday; the other two are serving prison terms.

Justice Department officials, who are also cracking down on Russian and other international crime organizations, say the Obama administration is bringing new energy to the fight against traditional organized crime. Attorney General Eric H. Holder Jr., has “renewed” the commitment that Robert Kennedy made against the mafia when he was attorney general in the 1960s, Breuer said.

Experts said the latest federal crackdown, while noteworthy, is targeting organized crime families who are already severely weakened. More than 7,000 organized crime figures have been convicted since the first major racketeering indictment against the mob in 1985, they said.

“The sizes of the cases they are bringing is significant,’’ said Jay Albanese, a Virginia Commonwealth University professor and organized crime expert, who characterized the current crackdown as “a continuation of the government’s effort of the past 25 years.’’

Bruce Maffeo, a former federal mafia prosecutor, said he applauds Holder’s “continued attention to the problem of organized crime. They are building on the success of prior administrations.’

“These cases will have a significant impact on La Cosa Nostra’s day-to-day operations,’’ Maffeo said.

In the Philadelphia indictment, the defendants were charged with crimes spanning more than a decade, including running an illegal electronic gambling business that supplied video poker machines and other devices to bars, restaurants and coffee shops.

The arrests followed charges in January against 127 people from seven East Coast organized crime families. That case produced the largest coordinated arrest, involving more than 800 law enforcement officers, in the history of the FBI’s mafia crackdown.