Chemical substances and technical devices were found at the house of a 19-year-old Austrian suspected of planning an attack on upcoming Taylor Swift concerts in Vienna, Austria, the public security director at Austria’s Ministry of Interior, Franz Ruf, told public broadcaster ORF’s Oe1 program in an interview Thursday.

Ruf added that these are still being evaluated by investigators. He previously confirmed during a press conference on Wednesday that chemical substances had been secured and were being evaluated.

Swift's three concerts in Vienna this week were canceled after two suspects were arrested Wednesday for allegedly plotting a terror attack, authorities said.

The cancellations came hours after authorities announced a 19-year-old Austrian citizen was arrested Wednesday morning and a second suspect was arrested in the afternoon.

This is a developing story. Please check back for updates.

ABC News' Aaron Katersky, Felix Franz, Will Gretsky, Emily Shapiro, Josh Margolin and Luke Barr contributed to this report.