Question: What community were the founding members of Islander 23's rival gang from?

full_context: Document 1: Westies: The Westies were a New York City-based Irish American organized crime gang, responsible for racketeering, loan sharking, bookmaking, number writing, contract killing, drug trafficking, murder, illegal gambling, and extortion. They were partnered with the Italian-American Mafia, and operated out of the Hell's Kitchen neighborhood of Manhattan. According to crime author T. J. English, "Although never more than twelve to twenty members—depending on who was in or out of jail at any given time—the Westies became synonymous with the last generation of Irish in the birthplace of the Irish Mob..." According to the NYPD Organized Crime Squad and the FBI, the Westies were responsible for 60–100 murders between 1968 and 1986.
Document 2: Milperra massacre: The Milperra Massacre, Milperra bikie shoot-out or Father's Day Massacre was a firearm battle between rival motorcycle gang members on 2 September (Father's Day in Australia) 1984, in Milperra, a south-western suburb of Sydney, New South Wales. The shootout had its roots in an intense rivalry that developed after a group of Comancheros broke away and formed the first Bandidos Motorcycle Club chapter in Australia. Seven people were killed and twenty-eight injured when the two groups clashed at Milperra. The event was a catalyst for significant changes to gun laws in New South Wales.
Document 3: MS-13: MS-13 (Mara Salvatrucha; also known as simply MS or Mara) is an international criminal gang that originated in Los Angeles, California, US in the 1980s. The gang later spread to many parts of the continental United States, Canada, Mexico, and Central America, and is active in urban and suburban areas. Most members are ethnically of Central American origin (principally El Salvador).
Document 4: Barrio Azteca: The Barrio Azteca (] ), or Los Aztecas (] ), is a Mexican-American gang originally based in El Paso, Texas. The gang was formed in the jails of El Paso in 1986 and expanded into a transnational criminal organization. They are currently one of the most violent gangs in the United States and are said to have over 3,000 members in the U.S. in locations such as New Mexico, Texas, Massachusetts and Pennsylvania and at least 5,000 members in Ciudad Juarez, Mexico.
Document 5: Apex (gang): Apex is a street gang in Melbourne, Australia. It was formed in 2012. The founding members were part of Victoria's South Sudanese community, although the gang later became more diverse, particularly after it merged with the YCW gang. Associated with violent car-jackings and burglaries, Apex came to prominence in the national media after a brawl in Melbourne's Central Business District between it and the rival Islander 23 gang in March 2016 after the Moomba parade. This prompted a crackdown by Victoria Police. They apparently have little structure and no official colours.
Document 6: Pomona 12th Street Sharkies: Pomona 12th Street Sharkies are a street gang in Pomona, California. Pomona 12th Street is the largest Hispanic gang in Pomona. The gang members are surenos and answer to the Mexican Mafia or La Eme. The gang uses a shark as a mascot. Pomona 12th Street gang will commonly abbreviate the name to "P12" or "PXII." Members will commonly wear Pittsburgh Pirate baseball hats because it displays a "P" on the front. Additionally, members have been known to wear Detroit Tigers baseball hats because it displays a "D" on the front which stands for "Doce" and translated from Spanish to English means the number 12.
Document 7: Westie (person): Westie, or Westy, is a colloquial term used in Australian and New Zealand English to stereotypically describe residents of the Greater Western Sydney, the western suburbs of Melbourne or the West Auckland city of Waitakere (New Zealand). It may also refer as a derogatory term to people who might not live in the west of a city. The alternative term "bogan" is often used instead, as it has a similar definition but does not refer to a geographical area.
Document 8: 2010 in organized crime: Around the world are countless groupings of individuals who deal exclusively or through a mix of legitimate and illegal activities. These Organized crime groups or criminal organizations are a transnational grouping of highly centralized enterprises run by criminals for the purpose of engaging in illegal activity, most commonly for the purpose of generating a monetary profit. The Omnibus Crime Control and Safe Streets Act of 1968 (federal statute - Public Law 09-351) states, "Organized crime means the unlawful activities of members of a highly organized, disciplined association..." They are called a number of different names including: the Mafia (US, Italy), Yakuza (Japan), Chinese Triads, the Irish Mob, the Neapolitan Camorra, the Calabrian 'Ndrangheta, the Indian Mafia, the Unione Corse, Serbian Mafia, and the Bulgarian mafia.
Document 9: Playboys (gang): Playboys 13 Gang, also known by the short name PBS13, is a violent, predominantly Hispanic street gang in West and East Los Angeles, California. They sometimes use the name Conejo or Rabbit gang. They align themselves with the Mexican Mafia, also known as La eme (which is Spanish for the letter M), while in prison and set aside their rivalry with other Sureño gangs. In some areas they refer to their houses and meeting or hang out areas as rabbit holes.
Document 10: Murri people: The Murri are the Indigenous Australians of modern-day Queensland, North West New South Wales. Collections of tribes and extended family groups throughout geographic regions of Australia have different names, such as the Yugarabul, the Jagera peoples from Coorparoo, Kwiambal peoples from Northern New South Wales and the Koori people of parts of New South Wales and Victoria. The term is their preferred term, expressing pride in their heritage and race.
Document 11: Rebels Motorcycle Club: The Rebels Motorcycle Club is an outlaw motorcycle club in Australia with around 70 chapters and 2,000+ members nationwide making it the largest club in the country. It was founded by Clint Jacks in Brisbane, Queensland in 1969 and was originally named the "Confederates". Their insignia is a Confederate flag with a cap-wearing skull and 1% patch in the centre. The Australian government and law enforcement consider the Rebels to be a criminal organisation but the club claims to be a group of motorcycle enthusiasts rather than gangsters. The National President is currently former Maltese boxer Alex Vella.
Document 12: The Avenues (gang): The Avenues, also known as Avenidas or AVE's, is a Mexican/Mexican American criminal street gang mostly in Los Angeles County, California. They originally started as a social club for local Latino youths to protect themselves from other violent youths. The Avenues, like most Mexican gangs in Los Angeles, are under the direct control of the Mexican Mafia when sent to State, County, or Federal prisons. They have a long history, but not all of it is riddled with violence and hate.
Document 13: Vatos Locos: Vatos Locos (in English, "Crazy Dudes") is a Street gang. Gangs using this name are active in several American states, Europe and Africa. The Vatos Locos originated in East LA but have extended their presence to Florida, Fort Pierce, Florida. They are mainly active in Fort Pierce's South 18th Street area by Delaware and around South 33rd Street and Orange Avenue. They represent their gang affiliation with black bandanas worn in the back right pocket of their pants. Their graffiti consists of "Vatos Locos," the Lowrider logo, or Lil Rob. These images are also present in gang tattoos. Vatos Locos are mainly Mexicans or Chicanos. Their dress consists of black shirts and khaki pants or shorts, and jewelry of chains or crosses. Most are supporters of the Oakland Raiders football team and show this by wearing similar colors.
Document 14: Blue Wedges: Blue Wedges is a conservation organisation in conflict with Australia's Victorian government policy to deepen shipping channels in Port Phillip and the large scale development of Ramsar listed Westernport. The Blue Wedges is a coalition of over 65 environmental and bay user groups opposed to development in the Melbourne Bays that they deem to be unsustainable, such as the Port of Melbourne Corporation's Channel Deepening Project. The Blue Wedges Coalition includes angling groups and peak bodies, professional fishing associations, diving and charter operators along with the more traditional coastal protection groups and bayside industry sectors. The Blue Wedges Coalition is supported in its goal to protect the bays by other environmental entities including the Victorian National Parks Association, Australian Conservation Foundation, Friends of the Earth, The Wilderness Society, Environment Victoria, Port Phillip Conservation Council and Western Region Environment Centre under a joint statement issued by these groups opposing the project and calling for action to stop the project from the Victorian Government.
Document 15: Islander 23: Islander 23 also known as I-23 is a Pacific Islander street gang in West Melbourne, Victoria, Australia. Islander 23 came to prominence in the national media after a large scale brawl in Melbourne's Central Business District between it and the rival gang Apex in March 2016 after the Moomba parade. It consists largely of youths from a South Pacific background.
ground_truth: Victoria's South Sudanese community