3rd teenager arrested in foiled attack on Taylor Swift concerts in Vienna

A third teenager has been arrested in connection with the foiled attack on now-canceled Taylor Swift concerts in Vienna, according to Austrian Interior Minister Gerhard Karner.

The 18-year-old Iraqi citizen was taken into custody in Austria's capital on Thursday evening after allegedly being in contact with the main suspect, a 19-year-old Austrian citizen who was arrested on Wednesday, Karner said Friday. A 17-year-old suspected accomplice -- another Austrian citizen -- was also arrested on Wednesday.

A 15-year-old Turkish citizen who had been detained for questioning is no longer being interrogated and has been released, a spokesperson for Austria's Ministry of the Interior said Friday. There is no arrest warrant for him.

The investigation into the foiled terror attack is ongoing and investigators are looking at the environment of the three arrested persons, the spokesperson said. Digital data carriers were found on the suspects and are now being analyzed, the spokesperson said.

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

"We have no choice but to cancel the three scheduled shows for everyone's safety," a message from Barracuda Music said. "All tickets will be automatically refunded."

The suspects allegedly radicalized themselves online, Franz Ruf, director-general for public safety in the Ministry of the Interior, said at a press conference. The 19-year-old suspect allegedly pledged allegiance to the leader of the Islamic State at the beginning of July, Ruf said.

Investigators are not convinced the alleged plot would have worked and they do not know if a functioning bomb was produced. However, Viennese investigators did find explosive precursor chemicals that showed a degree of motivation and planning, sources told ABC News.

Investigators in Austria are looking at surveillance footage to determine whether one or more of the suspects had previously visited the concert site for reconnaissance or if they had visited other potential targets.