Austrian prosecutors have filed terrorism-related charges against a 21-year-old who they say planned toattack one of Taylor Swift’s concerts in Vienna in August 2024.

Three dates in Swift’s record-breaking Eras tour were cancelled after authorities warned of the plot.

A spokesperson for the Vienna public prosecutors office confirmed on Monday that the defendant was in custody. Austrian media identified the suspect as Beran A and said he had been arrested in August 2024.

Prosecutors said the defendant had declared allegiance to Islamic State, sharing propaganda material and videos via various messaging services.

They accused him of having “obtained instructions on the internet for the construction of a shrapnel bomb based on the explosive triacetone triperoxide” typically used by IS, and of having produced a small amount of the explosive.

The defendant had made “several attempts” to buy weapons illegally outside the country and to bring them to Austria, prosecutors said.

They plan to proceed with a criminal case against the unnamed suspect in Wiener Neustadt, a town near the Austrian capital.

He is also alleged to have been involved in planning other attacks abroad, including in Dubai and Istanbul, though those attacks never materialised.

If found guilty, he faces up to 20 years in prison.

After the shows were cancelled, Swift wrote on social media: “The reason for the cancellations filled me with a new sense of fear, and a tremendous amount of guilt because so many had planned on coming to those shows.”

The US provided intelligence that fed into the cancellation decision.

“The United States has an enduring focus on our counter-terrorism mission,” the then White House national security spokesperson, John Kirby, said in August 2024. “We work closely with partners all over the world to monitor and disrupt threats.

“And so as part of that work, the United States did share information with Austrian partners to enable the disruption of a threat to Taylor Swift’s concerts there in Vienna.”

Last year a Berlin court convicted a Syrian teenager of contributing to the plot. The 16-year-old was given an 18-month suspended sentence.

Associated Press and Agence France-Presse contributed to this report