Mexican drug kingpin Ismael “El Mayo” Zambada, co-founder of the Sinaloa drug cartel, is in U.S. custody, the Justice Department said in a statement. They also announced the arrest of another Sinaloa cartel leader, Joaquin Guzman Lopez. Both men were arrested in El Paso.

“The Justice Department has taken into custody two additional alleged leaders of the Sinaloa Cartel, one of the most violent and powerful drug trafficking organizations in the world,” U.S. Attorney General Merrick Garland said.

In February, U.S. federal prosecutors charged Zambada with conspiracy to manufacture and distribute fentanyl, which has been identified as the leading cause of death for Americans aged 18 to 45.