New York, Mar 3 (IANS): More than a dozen members of a Los Angeles-based international criminal gang have been indicted over seven killings, including of three students in New York, a media report said.

The US Attorney's Office for the Eastern District of New York said the 13 members of La Mara Salvatrucha, known as MS-13, face offences including seven murder charges, racketeering, attempted murder, assault, obstruction of justice and arson in the 41-count indictment unsealed on Thursday, CNN reported.

"Law enforcement was determined that these brutal murders wouldn't turn into cold cases," US Attorney Robert L. Capers told the media.

Two of the students -- Nisa Mickens, 15, and Kayla Cuevas, 16 -- were beaten with baseball bats and a machete, Capers said.

The girls attended Brentwood High School in Brentwood, a working-class community in Suffolk county, about 45 miles east of New York City.

At the time, police said there appeared to be gang involvement in the girls' deaths and the deaths of two others, whose skeletal remains were found after they had been missing for months.

Police have not announced arrests in the latter two deaths.

Authorities said a third Brentwood High School student, Jose Pena, 18, was killed on June 3, 2016, reports CNN.

His skeletal remains were discovered on October 17, 2016, in a wooded area that served as a burial ground for MS-13 victims, Capers said.

Pena was killed because he was suspected of violating gang rules, federal authorities said.

MS-13 is one of the largest criminal organisations in the US, according to federal authorities.

It has more than 6,000 members in the US, including a presence in at least 46 states and the District of Columbia, officials said.

More than 30,000 members of MS-13 operate mostly in El Salvador, Mexico, Honduras and Guatemala.