What is "surenos"

Sureños, Sur 13, or Sureños X3 are groups of loosely affiliated gangs that pay tribute to the Mexican Mafia while in U.S. state and federal correctional facilities. Many Sureño gangs have rivalries with one another and the only time this rivalry is set aside is when they enter the prison system. Thus, fighting is common among different Sureño gangs even though they share the same common identity. Sureños have emerged as a national gang in the United States.