Story highlights Justice minister: The group was "absolutely amateur -- with no preparation"

No specific targets at the Rio Olympics were mentioned, he says

Rio de Janeiro (CNN) Brazilian police have arrested 12 people suspected of planning terrorist acts during next month's Rio Olympics, authorities said.

The group was inspired by ISIS and mostly organized online, Justice Minister Alexandre de Moraes said.

He said no specific targets were mentioned, but the Justice Ministry is still investigating the suspects' computers and cell phones to learn more about the possible plans.

De Moraes said the suspects are all Brazilian nationals, and that one minor was mentioned in the conversations.

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De Moraes said the group was not an organized cell, calling it "absolutely amateur -- with no preparation."