Eight Brazilians were arrested in July 2016 for organizing what authorities described as an "amateur" terrorist cell that had sworn loyalty to the Islamic State jihadist group (AFP Photo/Evaristo Sa)

Brasília (AFP) - Brazilian prosecutors filed terrorism charges Friday against eight people accused of plotting attacks and recruiting followers ahead of the Olympics in Rio de Janeiro last month.

The eight Brazilians were arrested in July for organizing what the authorities described as an "amateur" terrorist cell that had sworn loyalty to the Islamic State jihadist group.

Prosecutors said they had asked a court to charge them with "recruitment and promotion of a terrorist organization."

In an investigation dubbed Operation Hashtag, police intercepted messages sent using the cell phone application Telegram in which the suspects discussed "the idea that they had to step out of the virtual realm and start acting for real," prosecutor Rafael Brum told a news conference.

Two minors also participated in the group, he said.

The discussions included the possibility of staging an attack on the Games and tips on home-made bomb-making. But there was no evidence of a concrete plot or an actual link with the Islamic State group, he added.

The Brazilian authorities received an initial tip-off about the group from the FBI in the United States, prosecutors said.

Six other suspects remain under investigation.

The Olympics, which were held from August 5 to 21, went off without major incident despite security fears. Some 85,000 police and soldiers were deployed for the event.