A man and a teenager were arrested Saturday in Rio de Janeiro as part of a police operation that dismantled a group planning a bomb attack during a Lady Gaga concert in Copacabana, where an estimated two million people attended.

“Operation Fake Monster” was carried out by Rio’s Civil Police to stop a group that was “spreading hate speech and preparing a plan” that mainly targeted minors and LGBTQIA+ members of the public, said a police statement on Sunday.

The name of the operation refers to the use of fake profiles by the grooming group, who pretended to be Lady Gaga fans — known as “Little Monsters.”

As part of their investigations, police found the attackers were recruiting participants, including teenagers, to use “improvised explosives and Molotov cocktails” during the concert. They promoted it on social media, framing it as a “collective challenge.”

The group’s leader, an adult man, was arrested for illegally carrying a firearm in Rio Grande do Sul. A teenager was also arrested as part of the same operation for storing child pornography.

Police said that the group used social media to promote “the radicalization of teenagers, the dissemination of hate crimes, self-mutilation, pedophilia and violent content as a form of belonging and defiance among young people.”

During the operation, police carried out 15 search and seizure warrants in Rio, Sao Paulo, Rio Grande do Sul and Mato Grosso, where they seized devices and other elements to be analyzed as part of the investigation.

“We acted in a surgical manner to dismantle a network that co-opted young people into violent practices in a digital environment,” said Rodney da Silva, Integrated Operations and Intelligence director from the justice ministry. “Our main goal is to protect teenagers and prevent symbolic violence from migrating into reality.”

Despite the major threats of disruption, Lady Gaga gave a historic performance on Saturday night, a free concert with a stage located on the beach. With an estimated 2 million people in attendance, it was the biggest concert in her career. Early projections are that it was the largest audience for a female solo artist performance in history.

“Thank you for making history with me. The people of Brazil are the reason why I can shine,” she said in an emotional letter she wrote and read out to the public, accompanied by a Portuguese translator. “You’ve been waiting for me for more than 10 years.”