Taylor Swift's shows in Austria have all been cancelled due to terror threats

However, two people were arrested last night (7 August) on suspicion of planning Islamist terror attacks targeting the events.

65,000 fans had been expected to attend the concerts, with a further 22,000 anticipated to turn up outside the stadium.

"Due to confirmation by government officials of a planned terrorist attack at the Ernst Happel Stadium, we have no choice but to cancel the three planned shows for everyone's safety," the organisers said in a statement issued about the concert's cancellation.

They added: "All tickets will be automatically refunded within the next 10 working days."

Austria’s General Director for Public Security, Franz Ruf, said that authorities had arrested a 19-year-old Austrian citizen in Ternitz on Wednesday morning, with a second arrest occurring in Vienna later on.

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

Sky News reports that Austrian authorities are still searching for one or more people who may have had knowledge of the alleged plot.

NBC News said that Swift's team cancelled the concert despite security plans for the gigs. They also added that the plot was not planning an attack against Swift herself, but instead was said to be against the event as a whole.

Swift's Eras Tour is set to come back to the UK next, with five nights scheduled for Wembley from August 15.