A 19-year-old Islamic State sympathiser planned a suicide attack at a Taylor Swift concert in Vienna, the country's intelligence agency said on Thursday.
Austrian authorities detained two suspects Wednesday for allegedly plotting to attack one of three Vienna concerts by the US star, which had been due to start Thursday.
All three dates were cancelled on Wednesday, leaving disconsolate "Swifties" to gather in the Austrian capital.
The 19-year-old main suspect had confessed, saying he "intended to carry out an attack using explosives and knives", domestic intelligence agency (DSN) head Omar Haijawi-Pirchner told journalists.
"His aim was to kill himself and a large number of people during the concert, either today or tomorrow," he added. The concerts had been to run from Thursday to Saturday.
A second suspect, a 17-year-old Austrian, was employed at a facility management company that would have "provided services" at the Ernst Happel Stadium where Swift was to perform, said Haijawi-Pirchner.
The younger suspect, who has so far refused to talk to authorities, was "in the area" of the stadium when he was detained, said Haijawi-Pirchner.
Chancellor Karl Nehammer said there were "concrete and detailed" plans to commit a "blood bath".
Interior Minister Gerhard Karner said a "tragedy was averted".
"The situation was very serious", he added, particularly in view of last week's attack at a Taylor Swift themed event in Britain, where three girls were killed.
Explosives and detonators were found in a search of the main suspect's apartment, authorities said.
- Disappointed Swifties -
Austria's top security chief Franz Ruf told reporters the two suspects had recently made changes in their private lives.
The main suspect, an Austrian with Northern Macedonian roots, had changed "his appearance and adapted it to Islamic State propaganda", while the second, an Austrian of Turkish or Croatian origin, had broken up with his girlfriend, he said.
Ruf earlier confirmed that authorities had received information "from foreign partners" which led to the arrests, but he declined to specify which.
In Washington, a State Department spokesman declined to comment on whether US intelligence had helped foil the plot.
"We are in touch with the Austrian government about this," said State Department spokesman Matthew Miller.
"They've said it's an ongoing investigation, so I will leave it to them to speak to the details.
Austrian police had promised to ramp up security for the concerts while playing down any concrete danger, but organisers still cancelled Swift's shows, which had each been expected to welcome 65,000 fans.
Swift's fans gathered in parks and plazas across Vienna to share their disappointment. Dilyara Joldassova, a 23-year-old engineer who travelled from Kazakhstan for the show, said she was "broken-hearted".
- Major world tour -
Swift did not immediately comment on the decision to cancel the Vienna shows but after last week's attack in Britain attack said she was "completely in shock".
Three girls were killed and five people seriously wounded in the mass stabbing at a Swift-themed dance class in Southport, England.
According to Ruf, police "did everything humanly possible to ensure" that the Vienna concerts "could go ahead", but the cancellation decision was taken by the organisers.
The 34-year-old star had been due to bring her record-breaking "Eras" Tour, which began its European leg in Paris in May, to Vienna.
From France, the tour has visited Sweden, Portugal, Spain, the United Kingdom, Ireland, the Netherlands, Switzerland, Italy, Germany and Poland.
In Austria, the shows had been expected to bring in some 100 million euros, according to estimates by the Austrian news agency APA.
"Eras" is already the first tour to sell more than $1 billion in tickets and is on track to more than double that by the time it concludes in Vancouver in December.
Austria experienced its first deadly jihadist attack in November 2020, when a IS sympathiser went on a shooting rampage in Vienna, killing four people and wounding 23 before police shot him dead.