Taylor Swift's 'Eras' Concerts in Vienna Canceled Due to Planned Terrorist Attack

Taylor Swift's concerts in Austria have been canceled due to government concerns about a planned terrorist attack ... despite TMZ confirming two men were already arrested for the alleged plot.

Authorities aren't fully confident they've caught all the terrorists involved in the planned attack. They say the threat has been "minimized," but there is still an "abstract" threat that looms.

Vienna police say they arrested 2 Austrian citizens after a bomb squad found bomb-making materials in the home of a 19-year-old suspect.

Cops say both men were radicalized and had pledged allegiance to ISIS.

Authorities believe the men had targeted one of the 3 shows that were slated to begin in Vienna this weekend.

Vienna authorities said, "Taylor Swift The Eras Tour Vienna shows canceled due to government officials confirmation of planned terrorist attack ... We have no choice but to cancel the 3 scheduled shows for everyone's safety."

The venue will give full refunds to would-be concertgoers.