Brazilian police have arrested 10 people, and issued warrants for two more, who they say were radicalized online by the Islamic State group and were discussing plans to attack the Olympic Games, which begin here Aug. 5.
These are the first-ever arrests related to alleged Islamist terrorism in Brazil and the first use of an anti-terror law passed in March.
Brazil's intelligence agencies have little experience in combatting terrorism, which has raised questions about how prepared the country is to ensure security at the Olympics. But Minister of Justice Alexandre de Moraes said those arrested on Thursday were "amateurs" who had no specific target and that crime was a bigger security concern during the Games than terrorism.
Federal police say those arrested are all Brazilian nationals, that they had no actual contact with the Islamic State but consumed media from the group online, and communicated with each other through the message services WhatsApp and Telegram. The group members were located in 10 different Brazilian states and are between 20 and 40 years of age.
They called themselves Defenders of Sharia. The genders of the group members were not given by police.
"We decided to act before the threat grows," Mr. de Moraes told reporters in Brasilia, saying police made the arrests based on preparatory actions and conversations the group had about planning an attack, but that it was clear the group was disorganized. "A few days ago, they said they should start practising martial arts, for example."
Mr. de Moraes has said that foreign intelligence agencies are assisting with efforts for the Games, and that they were involved in gathering the information that led to these arrests.
He said that some members of the group had sworn an oath of allegiance to Islamic State and that they planned to carry out an Orlando nightclub-style mass shooting attack. They did not have bomb materials, he added.
One group member made plans to buy an automatic weapon online from a store in neighbouring Paraguay, the Minister said, which prompted the arrests. This was among the many odd details of the alleged plot, given that guns – even assault rifles – are widely available across Brazil and are openly carried by criminal organizations in, for example, some of Rio's favelas.
The police investigation, called Operation Hashtag, began in April and involved more than 130 officers.
Fernando Brancoli, an expert on international security who teaches at the Getulio Vargas Foundation in Rio, called the timing "convenient" for Brazil's government and its patchy international reputation.
"I really doubt this was any kind of organized group – I think it was a chaotic bunch of people exchanging messages on the Internet," he said. "But how interesting of government to do this right now, and call a fast press conference, when there is a lot of argument that Brazil can't manage security – this is very good for their image."
Mr. de Moraes insisted that crime is a much bigger threat to the Games than terrorism. "I reiterate that public security is more of a concern than terrorism, given the amateur nature of this cell."
He said members of the group wanted to travel to Islamic State-controlled areas but could not afford it, and that they acknowledged in their communications that Brazil is not part of the coalition against IS but concluded it was nevertheless a valid target as many foreigners would attend the Games.
Prof. Brancoli said Brazil was initially reluctant to accept any international support on intelligence issues, but the government shifted its position after attacks in France and Miami. "Brazil has no experience in this," he said. "But now it has a lot of help. There are police everywhere in Rio at this point. You can't say the chance is zero, but I'm not worried about the Games. I'm much more worried about what comes after the Games."
Brazilians on social media are mocking the arrests, noting that even the country's alleged terrorists are disorganized, unprofessional and scramble to get ready at the last minute.
Police seized computers and cellphones during the arrest raids, but no weapons. Those arrested will be held for 30 days, as per the new law.
Only one of the suspects, Levi Ribeiro Fernandes de Jesus, 21, of Curitiba, has been named by police. Officials there said he called himself Muhammad Ali Huraia in interactions on Islamist Facebook sites. Brazilian media report that a second of the suspects is a 21-year-old Sao Paulo man who converted to Islam six years ago.
Marcos da Silva, the judge who issued the arrest warrants, was more cautious than Mr. de Moraes in describing the group as a Brazilian terror cell. He said Thursday afternoon that further investigation would be needed to establish whether the group members really were intent on carrying out terrorist acts. "Not everything a person espouses in the virtual world will be realized in the real world," he said.