The 19-year-old suspect was detained on suspicion of planning an attack at a Taylor Swift concert

Police have found a number of disturbing items from the home of a man who was arrested on suspicion of plotting an attack on a Taylor Swift concert.

Officials have said that the 19-year-old suspect had carried out ‘concrete preparatory actions’ for the attack.

The suspect is an Austrian citizen and has previously posted an ‘oath of allegiance’ to terrorist group ISIS to an account online.

A 17-year-old suspect has also been arrested in connection with the plot.

General director for public security in Austria Frankz Ruf told the broadcaster ORF that Austrian authorities are considering the 19-year-old to be the main suspect in their investigations.

Mr Ruf said: “According to the current status of the investigation, the two suspects became radicalised via the internet.”

Searches were also undertaken at the residence of the older suspect, and uncovered what authorities believe is evidence of ‘concrete preparatory actions’.

Officers found a number of unsettling items at the address.

Three Taylor Swift concerts in Vienna were cancelled. (Thomas Niedermueller/TAS24/Getty Images for TAS Rights Management)

These included a number of chemicals and ‘technical devices’ at the address.

Police are now carrying out investigations into the plots, and believe the two individuals may have been part of a small group that they are looking into.

Taylor Swift had been due to play at the Ernst Happel Stadium in Vienna on Thursday, Friday, and Saturday.

However, organisers took the decision to cancel the performances amid growing concerns about the safety of attendees due to the threat of an attack.

In a post on Instagram, the organisers wrote: “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.

“All tickets will be automatically refunded within the next 10 days.”

Swift had been due to make three performances in Vienna. (Thomas Niedermueller/TAS24/Getty Images for TAS Rights Management)

Swift is currently on her Eras Tour, with concerts in Vienna expected to draw in some 65,000 people for each show.

There were also some 10,000 to 15,000 fans expected to be outside of the arena, police have shared.

Austrian Karl Nehammer posted on Twitter that while the cancellations would be a ‘bitter disappointment’ to fans, the situation had been ‘very serious’.

Nehammer added: “Thanks to the intensive cooperation of our police and [security agencies] with foreign services, the threat was recognized early, combated and a tragedy prevented.”

Investigations into the alleged plot are ongoing.

Taylor Swift is yet to make a public statement about the cancellations.