Suspected MS-13 gang members arrested in connection with Long Island teen murders Authorities will announce the arrests at a news conference this afternoon.

 -- Several suspected gang members were arrested in New York this morning on federal charges, including the brutal murders of three teenagers in Long Island last year, authorities said.

"The murders, particularly of these two girls, young ladies, were particularly heinous," Robert Capers, the United States Attorney for the Eastern District of New York, said at a news conference today. "They were beaten to death in the street with machetes and bats over seemingly nothing and left in the streets or in the backyard of a house to die. These were terribly heinous crimes."

While the prosecutor declined to discuss specifics of how they apprehended the suspects, Capers suggested catching the members of the gang required the cooperation of other immigrants in the community.

"The message we are getting across to the community is we’re here to serve and protect," he told reporters. "And the only way we can effectively do that is with the assistance of the community.”

Charges against the 13 suspected gang members, unsealed in federal court today, include seven murders, attempted murders, racketeering, assaults, obstruction of justice, arson, conspiracy to distribute marijuana and related firearms and conspiracy charges, according to a press release from the U.S. Attorney’s Office.

Four of the suspects were arrested earlier this morning by FBI and local police and were arraigned this afternoon at the federal courthouse in Central Islip, Capers said.

It was not immediately clear if any of the suspects have entered pleas or are currently represented by attorneys.

Officials said the suspects are members of a segment of the MS-13 gang that came to Long Island from El Salvador. Ten of the 13 defendants in this case are in the country illegally, including all of the defendants charged with the murders.

Among the offenses added in the second superseding indictment are murder charges against 22-year-old Alexi Saenz, 19-year-old Jairo Saenz, 29-year-old Edwin Amaya-Sanchez and 19-year-old Enrique Portillo in connection with the Sept. 13 killings of 16-year-old Kayla Cuevas and 15-year-old Nisa Mickens in Brentwood, a town on Long Island.

Authorities believe the double murder stemmed from disputes and altercations Cuevas and several friends had with MS-13 gang members at Brentwood High School.

"The day Nisa Mickens and Kayla Cuevas were heinously murdered, the Suffolk County Police Department made a commitment to their families and to the residents of Brentwood that justice would be served. Today, in collaboration with the FBI and the United States Attorney's Office, we have delivered on that promise," Suffolk County Police Department Commissioner Timothy Sini told reporters.

Murder charges against 19-year-old Elmer Alexander Lopez, 18-year-old German Cruz and two other defendants, who authorities said are still fugitives at this time, in connection to the June 3 killing of Jose Pena were also added in the second superseding indictment. Pena attended Brentwood High School and his remains were found on Oct. 17, officials said.

"These recent arrests in a combined multi-jurisdictional law enforcement effort should be a prime example of how these heinous murders by gang members will not go unpunished," Nassau County Police Department Acting Commissioner Thomas Krumpter told reporters.

Two other suspected MS-13 gang members, who were juveniles at the time of the murders, have been charged in connection with the deaths of Cuevas and Mickens. A third juvenile suspected MS-13 gang member has been charged in connection with Pena's murder. Those cases remain under seal at this time by statute, officials said.

"The brutal murders of Nisa Mickens and Kayla Cuevas and the savage killing of Jose Pena, allegedly committed by these defendants, exemplify the depravity of a gang whose primary mission is murder," Capers told reporters.

"As the MS-13 continues its efforts to expand and entrench itself in our community, both by sending gang members to illegally enter the United States from Central America, and by recruiting new members from our schools and neighborhoods," he continued, "this office and the FBI's Long Island Gang Task Force will continue our mission to dismantle the MS-13 and free our neighborhoods from the terror they cause."

MS-13 is believed to have been formed in the late 1980s in Los Angeles, when residents of El Salvador fled a civil war that left 75,000 people dead. The gang later grew in El Salvador after several members were deported back to the country. El Salvador is now the murder capital of the world, and MS-13 is one of the two main gangs in its capital, San Salvador.

"It’s extremely violent, as evidenced by their motto, 'mata, viola, controla,' which translated means 'kill, rape, control,'" Attorney for the District of Massachusetts Carmen Ortiz told ABC News in 2016.

MS-13, as well as rival El Salvadorian gang, Barrio 18, now have thousands of members in many U.S. cities, according to authorities.

MS-13 gang members have been recently tried for murders in other U.S. cities. In Houston, today, two known gang members who allegedly tortured and kidnapped one victim and killed another appeared in court to hear charges. Last May, six MS-13 gang members were convicted of the murders of three victims in Northern Virginia.