U.S. officials said Monday that two leaders of a white supremacist group who were also the inspiration for a Turkish youth stabbing five people in Eskişehir were arrested. They face charges of seeking to spark a "race war" and attacks on Jews, immigrants and members of the LGBTQ community using an online forum known as "Terrorgram."

Dallas Humber, 34, of Elk Grove, California, and Matthew Allison, 37, of Boise, Idaho, were taken into custody on Friday. "Today's indictment charges the defendants with leading a transnational terrorist group dedicated to attacking America's critical infrastructure, targeting a hit list of our country's public officials and carrying out deadly hate crimes – all in the name of violent white supremacist ideology," Attorney General Merrick Garland said in a statement.

Humber and Allison face multiple charges including soliciting hate crimes and the murder of federal officials, distributing bomb-making instructions and conspiring to provide material support to terrorists. According to the indictment, Humber and Allison used the encrypted Telegram platform to promote their white supremacist ideology and communicated with followers on a forum dubbed the "Terrorgram Collective." They promoted the belief that "violence and terrorism are necessary to ignite a race war and 'accelerate' the collapse of the government and the rise of a white ethnostate," it said. Humber and Allison allegedly joined Terrorgram in 2019 and became leaders of the group in 2022 after another leader was arrested. Followers were led to believe they could become "saints" by "committing an attack in furtherance of white supremacist accelerationism," the indictment said.

At least two attacks have been linked to Terrorgram, a livestreamed stabbing of five people by an 18-year-old man outside a mosque in Türkiye on Aug. 12 and the fatal shooting of two men at a gay bar in the Slovakian capital Bratislava in October 2022.

The Turkish attacker allegedly stated in a manifesto that he wanted to be recognized as a "saint," and the 19-year-old Bratislava assailant sent his manifesto to Allison and then killed himself, the indictment said. The Turkish attacker, identified as Arda K. was arrested on charges of attempts at multiple murders after he fled the scene. His victims were mostly elderly people resting outside the mosque in central Türkiye's Eskişehir. Arda K. was wearing a helmet and a skull mask similar to those worn by white supremacists in the United States. He was also carrying an axe and wearing a vest.

Turkish media outlets have reported that Arda K. confessed to carrying out the attack due to his "misanthrophy" and expressed admiration for Anders Behring Breivik, a convicted Norwegian neo-Nazi terrorist who killed dozens in two separate attacks in 2011 in Norway. A report by the Sabah newspaper says that Arda K. met a foreigner with the nickname of Fjotolf Hansen (Breivik's adopted name) online and received his assistance in planning his attack, including an aborted plot to carry out a bombing. Arda K. reportedly told investigators that he adhered to neo-Nazi ideology and shared the views of the Ku Klux Klan.

Humber and Allison "solicited others to engage in hate crimes and terrorist attacks against Black, immigrant, LGBT and Jewish people," Assistant Attorney General Kristen Clarke said at a news conference.

The pair also drew up a list of "high-value targets" for assassination, according to the indictment, which included a U.S. senator, a U.S. District Court judge and a former U.S. attorney, along with state officials and leaders of private companies. They also allegedly distributed an instructional video called "How to Make a Letter Bomb."