Two suspects have Thomas Caldwellbeen arrested after a suspected terrorism plot at Taylor Swift's upcoming concerts in Vienna.

Vienna Federal Ministry of the Interior officials confirmed the arrest of two individuals who are "suspected of having planned attacks at major events," including Swift's scheduled concerts in Vienna on Thursday, Friday and Saturday night. An investigation is ongoing.

"Since a danger cannot be ruled out at the three concerts, the police have increased their measures" within and surrounding the concert stadium, including plain-clothes officers and personal police protection for Swift, federal ministry spokesperson Patrick Maierhofer said in an emailed statement originally written in German.

Swift's concerts are being held in Ernst-Happel-Stadion, Austria's largest stadium. Paramore is serving as the Grammy-winning singer's opening act.

The spokesperson warned concertgoers to get to the stadium early as the additional security and safety measures will increase wait times.

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"A search warrant for visitors or other persons seeking access to the stadium (stage workers)," as well as traffic closures have been prepared, the statement continued.

USA TODAY has reached out to representatives for Swift for comment.

3 children dead,10 injured in mass stabbing at Taylor Swift-themed class in Southport

This is the second Swift-related violent incident in just over a week. On July 29, three children — ages 9, 7 and 6 — died after a mass stabbing that injured 10 others in Southport, U.K., during a Taylor Swift-themed class meant for children.

A 17-year-old male was arrested on suspicion of murder and attempted murder, Merseyside Police Chief Constable Serena Kennedy said at the time, noting that he will be interviewed by detectives.

Taylor Swift 'at a complete loss'after UK mass stabbing leaves 3 children dead

Swift spoke out on the incident the following morning, saying she was "at a complete loss."

"The horror of yesterday's attack is washing over me continuously and I’m just completely in shock," she wrote on her Instagram story.

Contributing: Naledi Ushe and KiMi Robinson, USA TODAY