Taylor Swift performs onstage during an Eras Tour stop in Amsterdam. Aldara Zarraoa/Getty

Austrian authorities on Friday announced a third arrest in connection with the foiled conspiracy to attack three now-canceled Taylor Swift concerts, even as disappointed fans charmed Vienna by trading friendship bracelets and singing the pop star’s songs in the streets.

The main suspect, a 19-year-old, planned to target onlookers gathered outside Ernst Happel Stadium — up to 30,000 each night, with another 65,000 inside the venue — with knives or homemade explosives during the concert on Thursday or Friday. The suspect hoped to “kill as many people as possible,” authorities said.

He was taken into custody on Tuesday, along with a 17-year-old, officials said. Both are Austrian citizens.

The third suspect, an 18-year-old Iraqi citizen, was arrested Thursday evening, the interior minister said at an unrelated news conference Friday.

A 15-year-old was also interrogated but was not arrested. Their names were not released, in line with Austrian privacy rules.

Swift is still set to travel to London’s Wembley Stadium for five concerts between Aug. 15 and 20 to close the European leg of her record-setting Eras Tour.

London Mayor Sadiq Khan said that while he understood Vienna’s reasons for canceling, “We’re going to carry on.”

Still, the Vienna plot drew comparisons to a 2017 attack by a suicide bomber at an Ariana Grande concert in Manchester, England, that killed 22 people. The bomb detonated at the end of Grande’s concert as thousands of young fans were leaving, becoming the deadliest extremist attack in the United Kingdom in recent years.

Coldplay is scheduled to play four nights at the same Vienna stadium later this month.

Authorities said the scheme was inspired by the Islamic State group and al-Qaida. The main suspect, as well as the 18-year-old arrested Friday, pledged “an oath of allegiance” to the Islamic State group.

Investigators discovered bomb-making materials at the main suspect’s home, as well as Islamic State group and al-Qaida material at the 17-year-old’s home. That suspect, who has so far refused to talk, was employed a few days ago by a company providing unspecified services at the venue for the concerts.

Although the 18-year-old swore the oath and “comes from the social environment” of the main suspect, Interior Minister Gerhard Karner said he is not directly linked to the plot.

The Austrian Interior Ministry, in a statement Friday to The Associated Press, said “his arrest underscores the broad scope of the ongoing investigation. Authorities are taking decisive action against anyone who might be involved in terrorist activities or exhibits radical tendencies.”

Investigators are scrutinizing the “networks” of the suspects, the statement said, and have turned to evaluating physical and electronic evidence.

Shiraz Maher, an expert on Islamic extremism with the Department of War Studies at King’s College London, said in a statement to the AP that attackers “prioritize casualties and therefore choose soft targets where they know large numbers of people will be congregating.”

Concert organizer Barracuda Music said it canceled the three-night Eras Tour run, scheduled to begin Thursday because the arrests were too close to showtime.

Heartbroken Swifties consoled each other on social media and in the streets of Vienna. After traveling from across the globe, hundreds gathered on Corneliusgasse, a small street just three miles from the stadium whose name echoes that of “Cornelia Street,” a contemplative synth-pop track from Swift’s 2019 album, Lover.

They sang Swift’s top hits, took selfies and traded friendship bracelets hanging from the branches of the only tree on the street. Swift fans often swap the beaded bracelets, typically bearing Swift’s song titles or popular phrases, with strangers at her concerts.

Huiyeon Kim, 22, took a 14-hour flight from South Korea to Vienna for the concert. On Friday, she was among some 300 fans spending the day on Corneliusgasse. She called the cancellation “so disappointing.”

“We couldn’t understand or believe it,” she told AP. “I think it was very very sad.”

Meanwhile, younger fans and their parents traveled to the Vienna Zoo for sightseeing — and discovered references to Swift’s songs among souvenirs in the gift shop, photos posted to social media show.

The lyric “Karma is a cat” — written in paper banners designed like friendship bracelets, of course — was nestled among stuffed felines, quoting “Karma” off the 2022 album Midnights.

Even as the fans belted out her hits, the superstar has not spoken publicly about the plot or canceled shows. “Taylor Nation,” a verified Instagram page widely believed to be run by her team, reposted the announcement from Barracuda Music, while her main account has not posted anything.

A representative for Swift did not respond to AP’s multiple requests for comment this week.

Last month, when a suspect in England killed three girls and wounded 10 people in a knife attack during a Taylor Swift-themed dance and yoga class, the performer said she was ”completely in shock” over the violence.