BOSTON (Reuters) - Sixty-six suspected members of three gangs in and around Boston were charged on Thursday after a coordinated wave of arrests aimed at breaking up a sprawling drug- and gun-smuggling operation, prosecutors said.

Thirteen people were charged in a federal racketeering indictment that contended they trafficked heroin, cocaine and guns with their serial numbers removed as part of the East Side Money Gang, prosecutors said in a statement. Others were charged with drug and gun violations.

More than 70 firearms, including semiautomatic handguns and rifles, were seized as some 400 law enforcement officers fanned out around the city early on Thursday to make the arrests, which also included members of the 18th Street and Boylston Gangs, prosecutors said.

U.S. Attorney Carmen Ortiz said in a news conference that the people arrested included the suspected leaders of the gang, and asked city residents to alert police to suspected criminal activity.

"We cannot solve crimes on our own," she said. "Help us reduce the violence and make the community safe."

Federal investigators had been following the alleged gangs since 2014, prosecutors said.

A total of 53 people, three of whom were already in custody, were charged in federal court, with 13 facing state charges.

The most serious charges, racketeering, carry maximum sentences of up to 40 years in prison.

(Reporting by Scott Malone; Editing by Richard Chang)