Brazilian authorities aided by U.S. Immigration and Customs Enforcement (ICE) Homeland Security Investigations (HSI) conducted an investigation leading to the arrest of four men involved in online threats, hate crimes and the planning of mass casualty attacks.

Operation Bergón, initiated in May due to the presence of neo-nazi groups on U.S. online platforms, resulted in 31 search warrants across seven Brazilian states leading to the seizure of weapons, Nazi paraphernalia, homemade explosives and detailed plans of future attacks. 

“Through continued investigative collaboration, members of dangerous anti-Semitic and neo-Nazi cells were apprehended before they caused a possible mass casualty event,” HSI Brasilia Acting Attaché Patrick Chen said in the release. “The success of Operation Bergón is a prime example of the importance of international partnerships in dismantling criminal organizations that threaten public safety and innocent lives.”

One of the men arrested, identifying himself to authorities as Matheus Hades NS, said he planned to utilize the explosives during a New Year’s celebration in São Paulo, Brazil, according to a report by Nokia News. The plan involved Hades NS killing several people and committing suicide, sparing those he considered “good, honest, hardworking people.”

“I’m not concerned about the rest,” Hades NS said to Brazilian authorities as reported by Nokia News.

The threats and planned attacks targeted Jewish and Black citizens of Brazil, the release said. The suspects are allegedly involved with Neo-Nazi cells planning and training for attacks on schools and public areas.