Brazilian police said they thwarted a bomb attack planned for Lady Gaga's concert on Copacabana beach in Rio de Janeiro on Saturday.

The Civil Police of Rio de Janeiro state, in co-ordination with the justice ministry, said suspects had recruited participants to carry out attacks using improvised explosives and the plan was aimed at gaining notoriety on social media.

The person responsible for the plan and a teenager were arrested, the police said.

Lady Gaga's team said they learned about the bomb threat only from media reports the morning after the gig. A crowd of more than two million people gathered for the concert, which was free to attend.

Police said the group that planned the attack had been spreading hate speech, mainly against children, adolescents and the LGBTQ+ community.

The alleged mastermind was arrested for illegal possession of a firearm in the southern state of Rio Grande do Sul, while the teenager was detained for storing child pornography in Rio.

Those responsible were also promoting the radicalisation of teenagers, including self-harm and violent content "as a form of belonging and challenge among young people".

A spokesperson for Lady Gaga told The Hollywood Reporter: "We learned about this alleged threat via media reports this morning.

"Prior to and during the show, there were no known safety concerns, nor any communication from the police or authorities to Lady Gaga regarding any potential risks."

The justice ministry said the suspects had identified themselves as Lady Gaga fans, known widely as "Little Monsters".

Police issued search warrants across the states of Rio de Janeiro, Mato Grosso, Rio Grande do Sul and Sao Paulo, and electronic devices and other materials were seized.

"Operation Fake Monster" was launched following a tip-off from Rio state police intelligence, which uncovered online groups encouraging violence among teenagers using coded language and extremist symbolism.

The concert was paid for by the city in an attempt to revitalise Rio's economy, with expectations it could bring in $100m (£75m).

In a massive security operation, 5,000 officers were deployed and attendees had to pass through metal detectors. Drones and facial recognition cameras were also used to police the event.

Lady Gaga, who last performed in Brazil in 2012, took the stage as part of a tour to promote her eighth album, Mayhem.

The singer wore Brazil-themed costumes for some of her acts, with outfits inspired by the national football team.

"You waited for more than 10 years for me," an emotional Lady Gaga told the huge crowd, holding out a Brazilian flag.