CNN  — 

Austrian authorities have arrested an 18-year-old Iraqi national in connection with an inquiry into an alleged ISIS-inspired plot to attack a Taylor Swift concert in Vienna, the country’s interior minister said Friday.

Organizers took the extraordinary decision on Thursday to cancel three Swift concerts in Austria after authorities said they foiled a terror attack planned for the Vienna leg of her blockbuster Eras tour.

The Iraqi teenager is the third person to be detained and is believed to have links with the main suspect, a 19-year-old Austrian with North Macedonian roots, according to the ministry. Both teenagers had recently pledged allegiance to ISIS, it said.

“A planned attack on a concert event was successfully thwarted thanks to the timely intervention of the authorities. This success was made possible through extensive investigations that targeted not only the main suspects but also their surrounding network,” it said Friday.

The ministry said authorities are “taking decisive action against anyone who might be involved in terrorist activities or exhibits radical tendencies.”

The Iraqi teenager is “not currently linked directly to the planned attack” but had been arrested under the “broad scope” of the ongoing investigation, it said.

The two primary suspects, the 19-year-old and a 17-year-old, are in pre-trial detention and had exhibited noticeable changes in their behavior before their arrests.

The 19-year-old suspect quit his job on July 25, saying he had “something big planned” and that he planned to detonate a device within the concert venue, Franz Ruf, Austria’s director general for public security, said Thursday.

Explosive devices and detonators were found at the home of the 19-year-old, as well as extensive ISIS propaganda material, 21,000 euros in counterfeit money, machetes, knives and anabolic steroids, Ruf said. The 17-year-old had recently broken up with his girlfriend.

A 15-year-old was also held and question but has since been released.

Fans ‘heartbroken’

Vienna was scheduled to be the penultimate venue of the European leg of Swift’s Eras tour. The US pop star was slated to play Thursday, Friday and Saturday in Austria, before playing five nights at London’s Wembley Stadium next week, then moving onto Canada for the tour’s final dates in November and December.

Austrian authorities said they expected around 65,000 audience members at each of Swift’s Vienna shows, with up to 20,000 fans outside the stadium.

The cancellation shook fans, including many who had traveled from across the continent and around the world for the shows.

Tiffany Kidd, a 41-year-old nurse from Arizona, had never left the United States, but had acquired her first passport, sewn several Swift-inspired outfits and spent $5,000 to fly to Vienna to watch the pop star perform live. The cancelations are “hearbreaking, for sure,” Kidd told CNN on Wednesday.

Vanessa Szombathelyi, 24, flew from Ireland to Hungary – where she and her best friend had planned to drive across the border to Vienna for the show. It would have been her first Swift concert since she first became a fan in 2018, and she’d been excitedly waiting since buying the ticket last summer.

“(I’m) feeling mixed emotions, everything from tears to being angry,” she told CNN on Wednesday, but said she was relieved that the suspects had been arrested.

The cancellations will also come as a blow to the Austrian economy. Swift’s tour has made headlines for providing an economic boom in the cities she visits, including generating an estimated $380 million in London, the city’s mayor said in June.