RIO DE JANEIRO -- Brazilian police arrested 10 people who allegedly pledged allegiance to the Islamic State of Iraq and Syria, or ISIS, on social media and discussed possible attacks during the Rio de Janeiro Olympics, officials said Thursday.
Justice Minister Alexandre de Moraes said in the capital, Brasilia, that 10 suspects had been detained and two more were being sought. All are Brazilian, and one is a minor. The gender of the people was not given.
Police acted because the group discussed using weapons and guerrilla tactics to potentially launch an attack during the Olympics, which begin Aug. 5, Moraes said.
However "they were complete amateurs and ill-prepared" to actually launch an attack, Moraes said. "A few days ago they said they should start practicing martial arts, for example."
Still, Moraes said even disorganized groups should be taken seriously.
The arrests were made in 10 different states, including Sao Paulo and Parana in the southern part of the country, and it was not clear whether the suspects knew each other beyond their online contacts. Moraes said there were no specific targets for an attack.
Moraes said they had all been "baptized" as ISIS sympathizers online and none had actually traveled to Syria or Iraq, the group's stronghold, or received any training. Several were allegedly trying to secure financing from the group.
The justice minister said one of the suspects communicated with a store in Paraguay via email in an alleged attempt to by an AK-47 assault rifle, apparently the most concrete action taken toward a possible attack. That email communication was intercepted by police.
Brazilians are allowed to possess small firearms but must have a license and training to do so. Only members of the military may possess assault weapons like the AK-47, although those and other firearms are common place especially in slums controlled by drug gangs.
Moraes said authorities seized computers, cellphones and other equipment, but no weapons.
Last week the top military aide for Brazil's interim government said concerns over terrorism had "reached a higher level" after the attack in Nice, France.
Officials did not raise the country's terror alert level Thursday following the raids.
Security has emerged as the top concern during the Olympics, including violence possibly spilling over from Rio's hundreds of slums. Authorities have said they will be prepared and that some 85,000 police and soldiers will be patrolling during the competitions.
Rio expects more than 10,000 athletes and half a million tourists. But the city that is already plagued by violent crime is battling a crime wave ahead of the games, reported CBS News correspondent Ben Tracy.
Human body parts recently washed up on Copacabana Beach next to the Olympic beach volleyball arena. Gunmen stormed a hospital to free a suspected drug trafficker and ended up killing a patient, and some Olympic athletes have been mugged on the street. But during the games, the Brazilian government said 47,000 police officers and 38,000 soldiers will be on patrol in Rio -- twice the size of the security force at the 2012 London Olympics.
Rio's state security secretary said the city's security apparatus -- including command centers -- was successful during the 2014 World Cup held in Rio and the pope's visit in 2013. Despite budget cuts, he said there is enough money to secure the games, but the security of the city before and after the Olympics will be worse. That is true in some of the poorest favelas, where the police are not always friendly.