The pop star had concerts scheduled in Vienna this Thursday, Friday and Saturday.

Before the shows were canceled, Ruf said security at the concerts would be increased. The shows were expected to draw 65,000 concertgoers per day, with an additional 10,000 to 15,000 fans outside of the area, police said.

At the 100th stop of the tour this summer in Liverpool, England, the 14-time Grammy winner told the audience the tour “has definitely been the most exhausting, all-encompassing, but most joyful, most rewarding, most wonderful thing that has ever happened in my life thus far.”

The “Eras Tour” will end in Vancouver, Canada, on Dec. 8.