A 21-year-old Austrian man has admitted plotting a jihadist attack on a Taylor Swift concert in Vienna in August 2024.
The man, named only as Beran A, also admitted to being part of a terrorist organisation, although he denied other charges including involvement in planning an attack in the Islamic holy city of Mecca in Saudi Arabia.
The state prosecutor told the court in Wiener Neustadt near Vienna that police had found an almost completed bomb during a search of the man's house.
Beran A was arrested after a tip-off from the CIA just before Swift's opening concert in Vienna in 2024.
As a result, all three sold-out gigs by the US superstar singer at Vienna's Ernst Happl Stadium were cancelled.
More than 195,000 people in total had been expected to attend.
Thousands of disappointed fans roamed the streets of the city, singing and exchanging Taylor Swift-themed friendship bracelets.
Beran A was brought into the courtroom, wearing a blue shirt and handcuffs, to face charges of terrorism and other offences.
He went on trial with another 21-year-old man, named as Arda K, who is accused of being part of an Islamic State cell with him. They are accused of planning attacks in Istanbul and Dubai, as well as in Mecca.
The main defendant's lawyer, Anna Mair, told the court: "My client has caused a great deal of fear and panic among many people, and he will have to answer for that, no question. But please try to look beyond the headlines."
Vienna prosecutors allege that Beran A started planning the attack at the latest by 21 July 2024. He was arrested on 7 August, a day before the first concert.
Prosecutors accuse him of declaring allegiance to, and spreading online propaganda online for, the jihadist group Islamic State, as well as making explosives and attempting to purchase weapons illegally.
He is suspected of having obtained instructions via the internet on how to make a shrapnel bomb, of a type "specific to IS attacks", according to the indictment.
Prosecutors accuse him of having received training from other IS members on how to handle explosives and of having made several attempts to purchase various firearms and a hand grenade through illegal dealers, with the intention of importing the weapons into Austria.
The two men, who were in their teens at the time of the attack, both face up to 20 years in prison if found guilty.
Last year, a teenager in Germany was also given an 18-month suspended sentence, for helping to prepare the foiled attack.
Prosecutors said the Syrian national, named as Mohammed A, helped Beran A with a translation of bomb-making instructions from Arabic and put him in contact with an IS member.
The trial is expected to continue until late May.
Taylor Swift - one of the world's biggest superstars - learned about the bomb plot in Vienna when she was on the plane to Austria, according to a documentary on the Eras Tour.
In her own words, she said the tour narrowly "dodged a massacre situation" when the CIA identified a plot to explode a bomb at the concert.
Speaking to select members of the media, including the BBC, at the New York premiere of her new six part Disney+ documentary, she said that after performing for 20 years "being afraid that something is going to happen to your fans is new".
In a post on social media after the incident in 2024, she wrote: "Having our Vienna shows cancelled was devastating.
"But I was also so grateful to the authorities because thanks to them, we were grieving concerts and not lives."
The 149-show Eras Tour kicked off in March 2023 and closed in December 2024.
It spanned five continents, selling more than 10.1 million tickets and becoming the first tour in history to surpass $1bn (£786m) in ticket sales.
