Organizers have canceled three Taylor Swift concerts in Austria after authorities arrested two suspects for allegedly planning a terror attack during the Vienna leg of her blockbuster Eras tour.

The extraordinary decision – which could come at significant cost to Vienna’s businesses – has devastated fans and renewed focus on the vulnerability of huge concerts as soft targets for terror networks and spree killers.

Swift was scheduled to play three shows in the European city from Thursday to Saturday – which have all been canceled, according to Barracuda Music, the promoter for Swift’s concerts in Austria.

“With confirmation from government officials of a planned terrorist attack at Ernst Happel Stadium, we have no choice but to cancel the three scheduled shows for everyone’s safety,” Barracuda Music said on Wednesday in a post online.

Swift’s official website also listed the concerts as canceled. CNN has reached out to Taylor Swift’s representatives for a comment.

Speaking at a press conference in the capital, police said a 19-year-old Austrian citizen, who they identified as a sympathizer of ISIS, was arrested Wednesday morning in Ternitz, lower Austria, while another arrest was made later in Vienna.

They had become “radicalized by the internet,” with the 19-year-old pledging his allegiance to the leader of ISIS in July, police said.

The two suspects had undertaken “concrete preparatory measures” for a terrorist attack after police suspected explosives were stored at the home of the suspect in Ternitz, authorities said.

Police also said that chemical substances were secured at the home of the 19-year-old and were being evaluated, the Associated Press reported.

Taylor Swift performs on stage at the Paris La Defense Arena as part of her The Eras Tour, in Nanterre, France, on May 9, 2024.

“From the current standpoint of the investigation we assume that the target of the attack were events in the Vienna region,” police said.

Later on Wednesday, police said they had made “further detentions” but did not give a number or any other details.

Barracuda Music said all tickets for the canceled shows will be automatically refunded within the next 10 business days.

Swift’s record-breaking Eras Tour began in Glendale, Arizona on March 18, 2023, and has been extended several times. It has since passed through the United States, South America, Asia and Australia, and is currently on its European leg before it makes a return to North America.

Cancelling three high profile shows will not have been an easy decision for Viennese authorities given the windfall Swift’s shows bring.

Her tour has made headlines for influencing the economies of the cities and countries that she visits – including boosting spending in the United Kingdom by nearly $1 billion, according to some estimates. It’s a stark illustration of her star power and the accompanying “Swiftonomics” that have accompanied her mammoth tour.

Vienna was scheduled to be the penultimate venue of the European leg, with Swift slated to play five nights at London’s Wembley Stadium next week before moving on to Canada for the tour’s final dates in November and December.

Authorities said they had expected around 65,000 audience members at each of Swift’s Vienna shows, and another 15,000-20,000 fans outside the stadium.

Just a day before the announcement of the Vienna cancelation, Swift posted on Instagram after performing in Warsaw, Poland: “I can’t believe we have 2 cities left on the European leg of The Eras Tour. It’s truly flown by. See you soon Vienna!

The cancelation has left fans both shaken and disappointed, including many who had flown in to Vienna for the shows.

Vanessa Szombathelyi, 24, had traveled from Ireland to Hungary – where she and her best friend had planned to drive to Vienna for the show. It would have been her first Taylor Swift concert since she first became a fan in 2018, and she’d been excitedly waiting since buying the ticket last summer.

“(I’m) feeling mixed emotions, everything from tears to being angry,” she told CNN on Wednesday, adding that she was “mad and grateful that the two people were caught.”

In recent years, music performances and venues in Europe have become targets for mass attacks by Islamist militants.

In November 2015, ISIS gunmen attacked the Bataclan theater in Paris – part of an assault that hit other targets in the city – killing at least 130 people in total.

And in May 2017, the group claimed responsibility for a suicide bombing at an Ariana Grande concert in Manchester, England, that killed 22 people.

Swift herself has called these types of attacks her “biggest fear.”

In a 2019 essay for Elle Magazine, she wrote: “After the Manchester Arena bombing and the Vegas concert shooting, I was completely terrified to go on tour this time because I didn’t know how we were going to keep 3 million fans safe over seven months,” referring to the 2017 mass shooting at a Las Vegas music festival that killed 60 – the deadliest by a lone gunman in the US to date.

“There was a tremendous amount of planning, expense, and effort put into keeping my fans safe,” she wrote at the time, adding that those fears have carried over into her personal life – with the star carrying around emergency first-aid equipment like bandage dressing for gunshot or stab wounds. (CNN)