A network of Turkish teenagers that called itself “Cehennemin 31. Katı” — “the 31st floor of hell” — has been linked by Turkish prosecutors to a series of murders, to the harassment of grieving families, and to the April 2026 school shootings. The group, organized on Telegram and Discord, was first reported in January 2024 over videos of cats being tortured. Twenty-seven months later, a 14-year-old opened fire in his school in Kahramanmaraş, killing a teacher and eight students. The Ankara Chief Public Prosecutor’s Office has since drafted an indictment describing a criminal organization “of a new kind” whose founder was 15.
One of the group’s Telegram channels had 109,000 members and another 22,000, according to T24 on 12 September 2025. In April 2026, police shut down a C31K channel with roughly 100,000 subscribers, according to Hürriyet on 16 April 2026.
“The 31st floor of hell,” founded by a 15-year-old
The name is a piece of cosmology: “Cehennemin 31. Katı,” shortened to “C31K,” means the 31st floor of hell. The founder is identified in the Ankara indictment by the initials A.T. He was 15 when he created the network, and used the handle “Ebu Cehil” — Abu Jahl, a figure in Islamic history known for his hostility to the Prophet Muhammad, according to columnist Tolga Şardan in T24 on 17 April 2026. Odatv wrote that the real identity of the “Ebu Cehil” leading the group could not be established.
Members entered the system between the ages of 14 and 16, according to the same indictment. Most used phone lines registered to their parents or relatives. The identified defendants were born between 2001 and 2007 and lived in Istanbul, Izmir, Kocaeli, Ordu, Şanlıurfa, Ankara, Zonguldak, Bitlis, Erzincan, Mersin, Tekirdağ, Elazığ and Kilis, according to T24 on 17 April 2026.
The first operation came on 13 January 2024. The Interior Ministry announced the arrest of five people in Istanbul, Mersin, Tekirdağ, Çorum and Karabük, on charges including animal cruelty, terrorist-organization propaganda and distribution of child sexual abuse material, according to Odatv on 13 January 2024. In the videos, members kicked or electrocuted cats. “This is how C31K kicks your cats. This is what happens to anyone who disrespects C31K,” read one caption, according to the same source.
From tortured cats to harassed families
The intelligence note that opened the Ankara investigation described the range of the group’s activity. It listed “images of torture against animals, abuse content targeting children, posts insulting national and religious values, false reports and threats directed at children under 18,” according to the text quoted by T24 on 17 April 2026. The note added that members called the families of people killed in earthquakes and fires “to use mocking expressions.”
The network also posted blackmail, sexual harassment and threats aimed at girls, shared locations while announcing bombings, and circulated messages insulting the families of soldiers killed in action, according to the same note. The group adhered to no fixed ideology. According to the indictment quoted by Odatv on 18 April 2026, it planned actions “to increase feelings of turmoil, hatred and hostility in society.”
On 12 September 2025, the Ankara prosecutor’s office ran a simultaneous operation across 14 provinces. Of 84 accounts analyzed, 40 suspects were identified, 17 of them minors; two were abroad. Thirty people were detained, 13 of them minors, according to T24 on 12 September 2025. The charges included violating cybersecurity law No. 7545, illegal access to computer systems, illegal recording of personal data, praising crime, and propaganda for terrorist and criminal organizations, according to Hürriyet on 12 September 2025.
Semih Çelik and Ahmet Minguzzi: the linked murders
On 4 October 2024, Semih Çelik killed two 19-year-old students, İkbal Uzuner and Ayşenur Halil, in Istanbul, before killing himself, according to Wikipedia (in Turkish). Four days later, on 8 October 2024, five C31K members were detained over a suspected link to Çelik, according to T24 on 12 September 2025. An examination of Çelik’s phone revealed exchanges with “incel” communities.
On 24 January 2025, Mattia Ahmet Minguzzi, 14, was stabbed in Kadıköy, Istanbul, by two minors; he died of his wounds, according to Wikipedia (in Turkish). His mother, Yasemin Minguzzi, began a campaign for justice. Her personal information then circulated in the group’s chats, and threatening messages she received during her campaign came from people presenting themselves as members of the community, according to T24 on 12 September 2025. The indictment names the Minguzzi case among the “socially sensitive” files the group targeted, according to T24 on 17 April 2026.
Fourteen provinces, an indictment, an anthem
After C31K was shut down, its members continued under the name C7K — “the 7th floor of hell.” The Ankara prosecutor’s office opened a new investigation after finding that the two groups acted in concert, and an operation on 25 November 2025 led to 14 detentions, according to Odatv on 25 November 2025. Five adult suspects were sent before the 27th High Criminal Court in Ankara, with prosecutors seeking sentences of 5 to 30 years, according to Odatv on 18 April 2026.
The indictment laid out an organizational chart. Derviş D. handled internal coordination; Dilara K. was an “admin” of the C31K and C7K groups and opened video calls to recruit; Boran S. carried out denial-of-service (DDoS) attacks, according to Odatv on 18 April 2026. The organization had an anthem, the “C7K marşı,” distributed on Spotify and YouTube. Members constantly created new groups while keeping the C31K and C7K labels. The channel “C7k #TEHLİKE” showed 45,489 members; on 24 November 2025, a call to action appeared there: “In front of a mosque, a flag will be taken down and burned, a C7k announcement will be made from the mosque, a man will be beaten in the street, reports will be filed against the families of fallen soldiers, animals will be tormented,” according to the same source.
Prosecutors called the structure a “new-generation criminal organization,” enabled by online technology and distinct from classical organizations, according to Odatv on 18 April 2026. The main group hosted subgroups under shifting names, including “#şeriat” and “#İsrailsohbet,” according to T24 on 17 April 2026. “We are facing Generation Z terrorism,” a senior police official said, according to the same source.
Siverek and Kahramanmaraş: the April 2026 shootings
On 14 April 2026, in the Siverek district of Şanlıurfa, Ömer Ket opened fire with a shotgun in a high school, wounding 16 people before killing himself, according to Yetkin Report on 15 April 2026. The principal had taken Ket’s social-media threats seriously and reported him to police, who detained him the day before the attack and then released him, according to the same source.
The next day, 15 April 2026, in Kahramanmaraş, İsa Aras Mersinli, a 14-year-old student, entered his school — the Ayser Çalık middle school in Onikişubat — with five handguns and seven magazines in his backpack. He killed a teacher and eight students and wounded 13, according to the toll announced the same day by Interior Minister Mustafa Çiftçi, reported by Yetkin Report on 15 April 2026; the toll later rose as critically wounded victims died, and the attack became the deadliest in Turkish school history, according to Wikipedia (in Turkish). The attacker died from a bullet from his own weapon, with no determination yet of whether it was suicide, said Governor Mükerrem Ünlüer. His father, U.M., is a former police intelligence officer, which investigators linked to the teenager’s access to the weapons.
After both attacks, the network’s Telegram channels celebrated the shooters and posted dates and locations for new attacks, according to Hürriyet on 16 April 2026. “Tomorrow a lot of customers have come up. We will organize attacks on schools,” wrote a user under the name “Barış Çelik,” according to the same source. Another added: “Business is open. Any school can be raided.” The group also circulated a price list for attacks.
That same day, six children were detained in Istanbul over messages naming a school in Üsküdar, and the C31K channel of roughly 100,000 members was shut down, according to Hürriyet on 16 April 2026. Nationwide, the General Directorate of Security announced 83 detentions, 940 social-media accounts blocked and 93 Telegram groups shut. “Respectfully announced to the public,” the official statement concluded, according to the same source.
The Interior Ministry’s “incel” report
On 11 May 2026, an Interior Ministry report on “the influence of social media on children” grouped C31K alongside the “901” and “Gülyan” groups, according to Odatv on 11 May 2026. The report describes individuals “unable to communicate with the opposite sex” who gather on Discord and Telegram to build a male-supremacist culture grounded in misogyny and racism. It presents these groups not as mere ideological deviance, but as hubs for serious crimes against children: bullying, sexual abuse, blackmail, credit-card fraud, animal cruelty and insults to Atatürk.
The group’s animal-torture videos carried a warning, reported by Odatv on 18 April 2026, which says it documented the threats two years earlier: “Today the animals, tomorrow your children.”
