Bomb-making materials were found in the home of one of two people suspected of planning a terror attack on upcoming Taylor Swift concerts in Vienna, authorities said Thursday, adding that both suspects appeared to be inspired by the Islamic State group and al-Qaeda.

The main suspect, a 19-year-old Austrian citizen, fully confessed to attack plans during an interrogation, according to Omar Haijawi-Pirchner, head of Austria’s Directorate of State Security and Intelligence.

Austria’s Director-General for Public Safety in the Ministry of the Interior Franz Ruf an..

The suspect was “clearly radicalized in the direction of the Islamic State” and allegedly intended to kill himself and “as many people as possible” outside the concert venue using knives and homemade explosives, Haijawi-Pirchner said at a news conference Thursday.

Members of media stand near the house of the main suspect, following the cancellati.

The 19-year-old, who was from the Austrian town of Ternitz and had North Macedonian roots, had been preparing for the attack since late July and drastically changed his appearance, according to Franz Ruf, the public security director at Austria’s Ministry of Interior. The 19-year-old researched bomb-making techniques and uploaded to the internet an oath of allegiance to the current leader of the Islamic State, Haijawi-Pirchner said.

A second suspect — a 17-year-old Austrian citizen — was arrested in Vienna on Wednesday afternoon. A 15-year-old Turkish citizen was also detained and questioned, according to Haijawi-Pirchner. No further suspects are being sought, Ruf said.

Each of the two suspects was known to police and both were said to have been involved in the direct preparation of the foiled attack, according to Haijawi-Pirchner. Most of the plans and preparations were made at the 19-year-old’s home, Ruf said.

The 15-year-old, who was interrogated, had been asked by the main suspect about ignition mechanisms, Haijawi-Pirchner said.

A general view of Ernst Happel Stadium on August 08, 2024 in Vienna, Austria.

The 17-year-old suspect, who has Turkish-Croatian roots, was employed a few days ago at a facility company providing services at the concert venue and would have been working there, according to Haijawi-Pirchner. It was discovered during the investigation that he was on the grounds of Vienna’s Ernst Happel Stadium, where Swift’s concerts were to be held.

Swift had concerts scheduled for Thursday, Friday and Saturday in Vienna.

When Ruf announced the arrests on Wednesday, he said security at the shows would be increased. Hours later, the concerts were canceled.

Taylor Swift performs at Wembley Stadium as part of her Eras Tour, June 21, 2024, in London.

“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 Vienna shows were expected to draw 65,000 concertgoers per day, with an additional 10,000 to 15,000 fans outside of the area, police said.