Unidentified suspects were “virtually recruiting participants to carry out attacks” to gain online notoriety, according to the Rio de Janeiro Civil Police.

A hate group posed as Lady Gaga fans online to radicalize young people and incite violence police said. The concert, with an estimated 2.5 million attendees, went on as planned.

Police in Brazil said on Sunday that two people have been arrested in connection with an alleged plot to detonate a bomb at a free Lady Gaga concert in Rio de Janeiro. The event, on Saturday, was the biggest show of the pop star’s career that drew some 2 million fans to Copacabana Beach.