In southern Brazil in July, Laureano Toscani and João Guilherme Correa were smoking cigarettes along a busy road in their prison-issued garb, shorts and sandals, waiting for a ride after seven months in jail.
Mr. Toscani was once convicted of stabbing a group of Jewish men, and Mr. Correa has been accused of murdering a couple leaving a party. But this time, they were behind bars for attending what they said was a harmless barbecue.
The Brazilian authorities, however, say it was something far more sinister: a meeting of the Hammerskins, a neo-Nazi group founded in Dallas in 1988 that they say has recently found its way thousands of miles south, to Brazil’s most starkly conservative region, reflecting a surge in far-right extremists in Latin America’s largest nation.
In September 2022, the state police in Santa Catarina began trailing the Hammerskins as members strategized on how to attract new recruits.
Two months later, as eight men met at a farmhouse outside the coastal city of Florianópolis, a police hate-crimes unit burst in, arresting everyone under anti-discrimination laws and accusing them of being members of the Hammerskins. Two other accused members were arrested weeks later.
On the members’ phones, the police said, they found antisemitic and racist content, including a message that one had sent in a group chat saying that “Black people need to die every day.” The police said they believed the group was aided by at least two American Hammerskin members who had traveled to Brazil several times.
The raid was part of a larger crackdown on neo-Nazi groups amid a rise in extremist movements and sentiments in Brazil that has spurred a greater number of school shootings and stabbing attacks, including at least 11 this year.
In February, a 17-year-old boy wearing a swastika armband was accused of throwing two homemade explosive devices into a school, but no one was injured.
In March, authorities said a 13-year-old boy fatally stabbed a teacher while wearing a skull mask commonly worn by an American neo-Nazi group.
And last month, a 16-year-old boy was accused of firing at a school, killing a classmate and wounding two others. Another student was injured trying to escape. The teenager had previously posted a photo of a swastika drawn on his face, the authorities said. In the three cases, which all occurred in or around São Paulo, the authorities arrested the boys.
The authorities say they have thwarted hundreds of other attacks.
Many of the attacks did not target Jewish people specifically. Brazil has roughly 100,000 people who identify as Jewish, according to estimates, or just one in every 2,000 people.
But researchers believe that those who have carried out or planned such attacks often turn violent after consuming extremist or neo-Nazi content online that frequently exhorts violence against any person who is not white.
In April, Brazil’s new justice minister, Flávio Dino, ordered the federal police to investigate what he called the growth of “hate and intolerant speech by neo-Nazi, neo-fascist and extremist groups.”
“If you mention Nazism, neo-Nazism, threaten a school or say you will attack a school, we will call for your arrest,” Mr. Dino added.
Brazil’s federal police have opened 21 investigations involving neo-Nazis so far this year, the same amount as in the three prior years combined.
Data on the size of Brazil’s neo-Nazi movement is sparse, but most researchers agree that it has been growing. One researcher tracking neo-Nazi groups, Adriana Dias, an anthropologist at the State University of Campinas, estimated that the number of groups increased from the hundreds in 2019 to more than 1,000 last year.
SaferNet, an organization that helps the Brazilian government combat online crime, has been collecting reports of neo-Nazi activity online since 2017, when it recorded almost 1,200 complaints. By 2021, complaints had grown to nearly 14,500, but they have since fallen as neo-Nazi groups have increasingly migrated to private-messaging platforms, researchers said. Still, there were 945 complaints in the first half of this year.
Antisemitic attacks have risen around the world, including in Brazil, since the war between Israel and Hamas broke out last month. Last month, the Brazilian Israelite Confederation received 467 reports of antisemitism, compared with 44 in October last year.
Some researchers linked the rise in neo-Nazi activity in Brazil to Jair Bolsonaro’s four years as president. Much like how American extremist groups gained strength during Donald J. Trump’s presidency, the Brazilian far right latched onto Mr. Bolsonaro’s inflammatory rhetoric as tacit approval of their views, researchers said.
After a state visit to Israel in 2019, Mr. Bolsonaro’s first year as president, he said that Nazis were leftists and that “we can forgive but not forget” the Holocaust, drawing criticism from his Israeli counterpart.
In 2020, Mr. Bolsonaro’s secretary of culture was forced to step down after giving a speech that was so similar to one by Joseph Goebbels, the Nazi Party’s chief propagandist, that parts seemed to have been copied.
And at a news conference in 2021, one of the former president’s aides made the “OK” hand gesture in front of cameras, a sign that has been appropriated to signify “white power” in white supremacist circles. He was charged with hate crimes, but the case was later dismissed.
The “gesture started appearing in the Brazilian far right, even among groups that do not explicitly identify as neo-Nazis,” said Odilon Caldeira Neto, a professor of contemporary history who studies the far right at the Federal University of Juiz de Fora. That, he added, helps neo-Nazi groups “get pulled into the political center.”
While the Bolsonaro administration investigated neo-Nazi groups, the issue has become a priority under the leftist president who defeated Mr. Bolsonaro last year, Luiz Inácio Lula da Silva. Raids on neo-Nazis groups have taken place in at least 10 states this year.
In July, the Brazilian police carried out a four-state operation against 15 people connected to a neo-Nazi group called the New SS of Santa Catarina, which used 3-D printers to manufacture handguns.
In one raid, the police were met with gunfire as they entered a rural home in Nova Petrópolis, a picturesque mountain town of about 20,000 people, many of whom are descendants of German immigrants.
The person firing at the police was a woman alone with her toddler and an infant. No one was injured and the police said they found two handguns, 96 rounds of ammunition and a trove of Nazi materials, including a swastika armband, German World War II memorabilia, the flag of an international neo-Nazi group and supplies to produce merchandise for a local neo-Nazi group.
The woman was arrested after firing at the police, but she was released on bail hours later.
Later that evening, belongings were still strewn at the home and the front door was busted. The woman who had been arrested said the items that the police had taken were personal belongings bought while traveling.
Many investigations have been concentrated in southern Brazil, where 73 percent of the population identifies as white, versus 43 percent nationally, and 62 percent voted for Mr. Bolsonaro last year, versus 49 percent nationally. Some researchers believe neo-Nazi groups are attracted to the region’s German history.
Before World War II, from 1928 to 1938, Brazil had the largest Nazi Party outside Germany, with 2,900 members across 17 states, according to Brazilian scholars. After the war, Brazil, like other South American nations, became a refuge for Nazis fleeing prosecution.
In 2020, the city of Porto Alegre, a southern state capital with a population of 1.5 million people, renovated a park to include an original design from the 1930s on the pavement. The design resembled a swastika, and residents complained. An investigation by the city concluded that there was no link between the design and the Nazi symbol. The design has since been vandalized.
Under Brazilian law, it is a crime to discriminate based on race, religion or nationality, as well as to display a swastika for the purpose of spreading Nazi ideology. Both crimes can lead to yearslong prison terms. All 10 people accused of being Hammerskin members have been released from jail with ankle monitors while they await court hearings.
Waiting for his ride from jail in July, Mr. Toscani said they had done nothing wrong. “They arrested us for throwing a barbecue,” he said. “You know what they found when they arrested us? A machete and a book.”
The book was “The Turner Diaries,” a classic of the extremist canon that Timothy McVeigh said inspired his bombing in 1995 of the federal building in Oklahoma City that killed 168 people.
Arthur Lopes, the chief of the Santa Catarina police hate-crimes unit, who arrested the accused Hammerskin members, said some were covered in extremist tattoos. “Everything but the swastika,” he said.
Jack Nicas contributed reporting from Rio de Janeiro.