NEW YORK (AP) — Federal prosecutors on Thursday announced charges against more than a dozen alleged high-ranking leaders of the international gang MS-13, accusing them of directing criminal activities including murder in the United States, El Salvador, Mexico and other countries over the past two decades.

An indictment unsealed by the U.S. Department of Justice in the Eastern District of New York details charges against 13 defendants including racketeering conspiracy, conspiracy to provide or conceal material support to terrorists and narco-terrorism conspiracy.

Four of the alleged gang leaders were expelled from Mexico and arrested by the FBI at George Bush Intercontinental Airport in Houston on Wednesday, according to a Justice Department statement. They face additional charges including alien smuggling conspiracy resulting in death and could receive the death penalty if convicted, prosecutors said.

Four other co-defendants are at large, while the rest are believed to be in custody in El Salvador pending possible extradition, the statement said.

The 13 defendants are part of MS-13’s command structure and play significant leadership roles in the organization’s international operations, according to the court filing.

Prosecutors said they authorized and directed violence including multiple murders in the United States, Mexico and elsewhere as part of an effort to expand MS-13’s influence and territorial control.

In El Salvador the alleged gang leaders operated military-style training camps for firearms and explosives, according to the indictment.

“The defendants have actively engaged in public displays of violence to threaten and intimidate civilian populations, to obtain and control territory and to manipulate the electoral process in El Salvador,” the DOJ statement said.

MS-13 is suspected of forging alliances with Mexican cartels and engaging in narcotics trafficking; immigrant smuggling and extortion; kidnappings; and weapons trafficking, the indictment said.