Media playback is unsupported on your device Media caption US Attorney General Eric Holder said the arrests were part of an ''ongoing fight against organised crime"

US federal agents have charged 127 suspected mobsters in multiple investigations into New York's organised crime families.

The arrests were made on Thursday morning throughout New York City, New Jersey, Rhode Island and other areas in the north-east US, FBI officials said.

They were accused of a range of crimes including murder and extortion.

Attorney General Eric Holder said the arrests were the largest single-day mob crackdown in the history of the FBI.

Analysis The authorities have warned against the notion that today's mobsters are more genteel or benign than the famed gangsters of the 1920s. The mafia isn't a thing of the past, they say. These crimes are very real, and some of them very brutal. But the power of New York's five mafia families has diminished in recent years. These arrests are the latest blow to their organisation. Beginning with the defection of a key mob figure in 1991, a number of informants have weakened New York's mafia network and its infamous code of silence. The testimonies of these defectors have led to long prison terms for key mafia figures. But authorities insist that today's arrests are not the end of organised crime in New York, just one more step in an ongoing struggle.

"We are committed and determined to eradicating these criminal enterprises and bringing their members to justice," Mr Holder said during a news conference in Brooklyn.

In a statement, the justice department officials said illegal mafia-imposed "taxes" on commerce, including at US ports and small businesses, have a negative impact on the US economy. Officials also said the groups had infiltrated labour unions and extorted union members.

"It [the mafia] is an ongoing threat to the economic well-being of this country," he said.

FBI Director Robert Mueller said: "Some believe organised crime is a thing of the past; unfortunately, there are still people who extort, intimidate, and victimise innocent Americans. The costs legitimate businesses are forced to pay are ultimately borne by American consumers nationwide."

Officials said alleged leaders of all the five major crime families in New York were arrested, including the entire leadership of the Colombo family not already in prison. In addition, the arrests hit the Gambino, Genovese, Lucchese, Bonanno, and DeCavalcante families.

Decades of offences

The arrests were made as the result of information obtained through wiretaps, co-operation from informants and other central intelligence, said Janice Fedarcyk, FBI's New York division.

Former mob members, who recorded thousands of hours of conversations with mafia family bosses, also assisted in the investigation, authorities said.

Indictments released on Thursday charge the suspects with crimes that include arson, extortion, gambling, loan sharking and labour racketeering.

Mr Holder said the charges spawned from decades of offences, including murders within rivalling crime families, a killing during a botched robbery and even a double homicide after an argument in a pub.

The sweep began before dawn on Thursday with some 800 federal agents and police officers arresting a range of individuals in the US, from suspected small-time bookers to senior family leaders. One person was also arrested in Italy in connection with the investigation.

Double-crossing

Mafia families in the US have seen a sharp decline in fortunes in the past 10 years as the result of court testimony from informants, who have begun breaking their code of silence in recent years.

Former mafia member Salvatore Vitale was sentenced to prison in October after federal officials and prosecutors praised his work in double-crossing his own crime syndicate.

Vitale, who was arrested in 2003, gave authorities information on at least 11 murders, which helped bring down the once prominent Bonanno family in the New York area.

John "Sonny" Franzese, a 93-year-old member of the Colombo crime family, was also sentenced in Brooklyn on Friday to eight years in prison for extorting strip clubs and a pizzeria in the New York Metro Area.