Top 10 most dangerous prison gangs in the world

Prison walls rarely stop organised crime; they often reinforce it. Around the world, hardened criminal networks have used correctional facilities as recruiting grounds, command centres, and even courtrooms of their own, running drug empires, ordering assassinations, and enforcing brutal codes of conduct from behind bars.

Here is a look at ten of the most dangerous prison gangs shaping crime today.

Formed in California's San Quentin State Prison in the 1960s, the Aryan Brotherhood is a white supremacist prison gang with a small but disproportionately violent membership. Despite counting only a few thousand members nationwide, the group is linked to a significant share of prison murders in the US federal system. Its activities include drug trafficking, extortion, and contract killings carried out both inside prison walls and against targets on the outside.

Born in the California prison system in the late 1950s, the Mexican Mafia, known on the streets as La Eme, controls much of the Hispanic prison population and drug trade across Southern California. The gang levies "taxes" on street-level drug dealers who must pay a share of their earnings to operate, and it settles disputes through violence coordinated from inside prison walls.

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Nuestra Familia was established in 1968 to protect rural Latino inmates from the Mexican Mafia, and the two groups have waged the longest-running gang war in California ever since. The gang is estimated to be responsible for hundreds of murders over several decades and relies on released members to smuggle drugs and contraband back into prison facilities.

Barrio Azteca emerged in the late 1980s among Mexican-American inmates in the Texas prison system before expanding its reach across the US-Mexico border. The gang have forged close ties with Mexican cartels, particularly in the Ciudad Juárez drug corridor, and have been linked to mass killings, kidnappings, and cross-border trafficking operations that blur the line between prison gang and cartel enforcer.

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Originally formed by Salvadoran immigrants in Los Angeles before spreading back to Central America through deportations, MS-13 has become one of the most feared transnational gangs in the world. Inside El Salvador's overcrowded prisons, MS-13 leaders have historically directed extortion rackets and violent campaigns on the outside, contributing to some of the highest homicide rates recorded anywhere in the world before the country's recent mass-incarceration crackdown.

Founded inside a São Paulo prison in 1993 in response to inmate mistreatment, the PCC has grown into one of the most powerful criminal organisations in South America. It now controls major cocaine trafficking routes stretching from Brazil to Europe and West Africa, and it operates with a paramilitary-style command structure that allows imprisoned leaders to direct operations across the country.

Comando Vermelho, or the Red Command, formed in the 1970s inside a Rio de Janeiro prison when political prisoners and common criminals shared cells during Brazil's military dictatorship. The alliance produced one of the country's oldest and most entrenched criminal factions, which today controls drug trafficking and territory across many of Rio's favelas, often clashing violently with the rival PCC for dominance.

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Among the oldest prison gangs in the world, South Africa's Numbers Gang traces its roots to the late 1800s and the mining compounds of the Witwatersrand, built around the folklore of a bandit named Nongoloza. Today it operates as three factions, the 26s, 27s, and 28s, each with its own role, code, and hierarchy inside South African prisons. The '27s' are considered the most feared enforcers of gang law, while the '28s' and '26s' handle protection and smuggling, respectively, with violence, tattoos, and ritual central to the gang's culture.

Formed in 1995 at Kumla high-security prison, Brödraskapet, meaning "the Brotherhood", is one of Scandinavia's most notorious prison gangs. Members have been tied to drug and arms trafficking, extortion, and murder, and the group has maintained influence in Sweden's prison system for decades despite repeated crackdowns by Swedish authorities.

Tren de Aragua originated inside Venezuela's Tocorón prison, where its leaders effectively ran the facility as their own headquarters before a major government raid in 2023. Since then, the gang has expanded rapidly across Latin America, with operations reported in Colombia, Peru, and Chile, and has become a focal point of international law enforcement concern over cross-border human trafficking and organised crime.