MAINZ, Germany — The prime suspect in a plot to attack Taylor Swift’s upcoming Eras Tour shows in Vienna confessed that he had planned to kill himself and a large number of other people with knives and explosive devices, officials in Austria said Thursday.

The 19-year-old Austrian with North Macedonian roots had downloaded manuals for bomb building, Omar Haijawi-Pirchner, head of Austria’s Directorate of State Security and Intelligence, said at a news conference.  

They also found…