Taylor Swift's three concerts in Vienna this week were cancelled after the government confirmed a planned attack at the stadium, the organizer announced late on Wednesday, and Austria's Chancellor Karl Nehammer said "a tragedy was prevented".

"Thanks to the intensive cooperation of our police and the newly established DSN with foreign services, the threat was identified early on, combated and a tragedy prevented," Nehammer said in a post on social media platform X. DSN is Austria's Directorate for Security and Intelligence.

"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 in a post on Instagram, adding all tickets would be automatically refunded.

Austrian police on Wednesday detained two people suspected of plotting attacks on concerts, Franz Ruf, director general for public security, said at a news conference on Wednesday evening.

"During our investigations, we identified preparatory actions and noted that the 19 year-old suspect had a particular focus on the Taylor Swift concerts in Vienna," Ruf said, adding that the suspect, an Austrian citizen, had pledged allegiance to Islamic state. Another suspect was later arrested in Vienna.

Police searched the residence of one of the suspects in Ternitz, Lower Austria, and were analysing items from the home. Local media, citing police sources, said three suspects were still on the run.

Earlier on Wednesday before the cancellation announcement, police had said the events would take place but with increased entry checks and personal searches, with deployment of special units including anti-terror and bomb disposal teams, advising the public to arrive early at the events.

Three Taylor Swift concerts were scheduled to take place In Vienna from Thursday to Saturday. Police had been expecting around 65,000 attendees at each show, as well as up to 15,000 people outside the stadium without tickets, which fed security concerns.

The shows were to be part of the record-breaking Eras Tour by the American singer-songwriter which started on March 17, 2023, in Glendale, Arizona, U.S., and is set to conclude on Dec. 8, 2024, in Vancouver, Canada.

Swift, 34, has not yet commented on the cancellations on her official Instagram account which has 283 million followers.

The singer has been taking Europe by storm, prompting some pundits to envisage an economic windfall as fans flock to dozens of sold-out shows from Dublin to Warsaw and beyond.

After Vienna, Swift was set to sing in London where six concerts are scheduled at Wembley Stadium, starting on Aug. 15.