Brazilian police have arrested 10 members of a group alleged to be preparing acts of terrorism, two weeks before the start of the Olympic Games.
They were not members of so-called Islamic State but had tried to make contact with the group.
The justice minister said the group was in the planning stage of an attack and police acted as a preventative measure.
The Minister described the cell as "absolute amateurs" and "ill-prepared" to launch an attack.
All those arrested were Brazilian and two more suspects were being sought, he said.