U.S. pop megastar Taylor Swift revealed on Wednesday that a "new sense of fear" came over her after authorities uncovered a plot to attack her Vienna concert venue as well as guilt for letting down fans by canceling her three shows in the city.

The singer also applauded authorities for foiling the plan to cause mass harm at Ernst Happel Stadium, the venue where she was scheduled to play.

"Thanks to them, we were grieving concerts and not lives," Swift said on Instagram in her first public comments since news of planned attack surfaced two weeks ago.

Police in Austria arrested a 19-year-old man who they said confessed to wanting to cause a "bloodbath" at Swift's Eras Tour shows.

"Having our Vienna shows canceled was devastating," Swift said. "The reason for the cancellations filled me with a new sense of fear, and a tremendous amount of guilt because so many people had planned on coming to those shows."

Swift said she decided "all of my energy had to go toward helping to protect the nearly half a million people I had coming to see the shows in London."

The London dates took place without incident and concluded on Tuesday, ending the European leg of the record-breaking Eras Tour.

The singer said she had not commented earlier because she did not want to risk provoking harm at future concerts.

"Let me be very clear: I am not going to speak about something publicly if I think doing so might provoke those who would want to harm the fans who come to my shows," Swift wrote. "In cases like this one, 'silence' is actually showing restraint."

The Eras Tour, the highest-grossing concert tour in history, is now on a scheduled break. It will resume with final dates from October through December in the United States and Canada.