VIENNA, Austria (AFP) — The Vienna leg of a tour by American mega-star Taylor Swift has been canceled after Austria arrested an Islamic State (IS) sympathizer in connection with an attack plot, the organizers said Wednesday.

Authorities had earlier confirmed the arrest of a 19-year-old sympathizer of the armed group for allegedly planning an attack in the Vienna region, warning he had a “focus” on Swift’s three upcoming shows.

“With confirmation from government officials of a planned terrorist attack at Ernst Happel Stadium, we have no choice but to cancel the three scheduled shows for everyone’s safety,” Barracuda Music said on Instagram.

The organizers added that all ticket holders would receive refunds. About 65,000 spectators were expected at each show scheduled for Thursday, Friday and Saturday.

The man, who had pledged his allegiance to IS “in recent weeks,” was detained in Lower Austria about an hour from the capital early on Wednesday, Austria’s top security chief Franz Ruf told a press conference.

“We have established corresponding preparatory acts and also that there is a focus of the 19-year-old perpetrator on the Taylor Swift concerts in Vienna,” Ruf said.

He said that chemical substances had been seized at the suspect’s home.

A second person believed to have been in contact with the suspect was arrested in Vienna.

According to the initial investigation, both suspects radicalized themselves on the internet.