The city's East Boston neighborhood was among sites of police raids that netted dozens of suspected members of the notorious and violent MS-13 gang late last week.

In all, 56 alleged members of the El Salvador-based outfit “La Mara Salvatrucha” have been indicted, according to an announcement on Friday. Many are in custody following raids in East Boston, Chelsea, Everett, Lynn, Revere and Somerville, officials said.

Fifteen had already been in custody and 18 remained at large on Friday. Thirteen faced immigration charges.

The suspects ranged in age from 19-44. 

The early morning arrests — which were carried out by 400 officers with the FBI, the Department of Homeland Security and state and local police —  followed episodes of violence in Eastie connected to the reputed criminal enterprise, among them the recent East Boston murders of 15-year-old Wilson Martinez, 16-year-old Irvin de Paz and 16-year-old Cristofer Perez de la Cruz.

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Law enforcement believe gang violence also to blame two weeks ago when shots rang out at Maverick Station on the Blue Line, also in East Boston. Police continue to pursue the suspect in that case, 21-year-old Eastie resident Rogelio Alvarado.

The raid spread new awareness in the area about the violent tendencies in MS-13 — described by U.S. Attorney Carmen Ortiz’s office as the first and only street gang in the U.S. labeled a “transnational criminal organization” with an East Coast foothold in the city.

The details emerged in testimony on Friday, as law enforcement showcased a table splayed with seized weapons and a poster filled with the faces of the alleged gangsters under the banner: “Operation Mean Streets.” 

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Investigators believe MS-13 recruited new teenaged members in area schools, including East Boston High. Gang members encouraged new recruits, some as young as 14, to commit gruesome crimes to gain status — attacking victims with machetes, knives and chains, Ortiz’s office has alleged.

Their official motto, translated to English: “kill, rape, control,” Ortiz said.

Charges for the suspects include racketeering, murder, conspiracy, firearms violations, immigration offenses and drug trafficking.