An 18-year-old <a href="https://www.thenationalnews.com/mena/iraq/" target="_blank">Iraqi</a> citizen was arrested on Thursday evening in connection with a planned terrorist attack on a concert hall in Vienna where <a href="https://www.thenationalnews.com/arts-culture/music-stage/2024/08/08/taylor-swift-vienna-concert-dubai/" target="_blank">Taylor Swift </a>was due to perform, as police investigate the network behind the foiled conspiracy. Experts told <i>The National</i> that the age of the three suspects, all teenagers, fits a pattern seen in recent months of younger plotters inspired by ISIS who have been radicalised online. The main suspect, a 19-year-old, planned to target onlookers gathered outside Ernst Happel Stadium – up to 30,000 each night, with another 65,000 inside the venue – with knives or homemade explosives during the concert on Thursday or Friday. The suspect hoped to “kill as many people as possible”, authorities said. He was taken into custody on Tuesday, along with a 17-year-old who had obtained a job at the venue, officials said. Both are Austrian citizens. A 15-year-old was also interrogated but was not arrested. The main suspect has North Macedonian roots, pledged allegiance to the <a href="https://www.thenationalnews.com/tags/isis/" target="_blank">Islamic State</a> and made a full confession in custody, said <a href="https://www.thenationalnews.com/tags/austria/" target="_blank">Austria's </a>general director for public security, Franz Ruf. The teenager is believed to have pledged allegiance to the branch of Islamic State based in the Khorasan province of Afghanistan known as <a href="https://www.thenationalnews.com/news/us/2024/07/11/terror-groups-operating-out-of-afghanistan-pose-significant-threat-un-report-says/" target="_blank">ISIS-K.</a> He swore allegiance to the <a href="https://www.thenationalnews.com/tags/terrorism/" target="_blank">extremist</a> group's leader on the internet and had chemicals, machetes and technical devices at his home in the town of Ternitz in preparation for an attack, said Mr Ruf. Although the 18-year-old swore the oath and “comes from the social environment” of the main suspect, Austrian Interior Minister Gerhard Karner said he is not directly linked to the plot. The Interior Ministry, in a statement, said “his arrest underscores the broad scope of the ongoing investigation. Authorities are taking decisive action against anyone who might be involved in terrorist activities or exhibits radical tendencies.” Investigators are scrutinising the “networks” of the suspects, the statement said, and are evaluating physical and electronic evidence. Recent research showed that two-thirds of ISIS-linked arrests in Europe in the past nine months have been of teenagers. The study of 27 ISIS-linked attacks or disrupted plots since October, carried out by <a href="https://www.thenationalnews.com/sport/olympics/2024/07/18/paris-olympics-faces-twin-terror-threats-of-isis-and-teenage-extremists/" target="_blank">Peter Neumann</a>, professor of security studies at King’s College London, revealed that of the 58 suspects, 38 were aged between 13 and 19. Floris Bosscher, a Europe analyst at Sibylline, geopolitical risk advisory company, said the ages of those arrested in relation to terror plots appears to be getting younger. “One of the things that we are seeing is the perpetrators are very young. That does signify a trend across Europe over the past 12 months,” he told <i>The National</i>. “A suspicion among intelligence professionals is that this comes from increasing infiltration by terrorists on social media. “For instance ISIS-K being active on TikTok, targeting specifically younger children, because they are relatively easy to radicalise and easy to influence.” Mr Bosscher said teenagers in general might be easier to influence online for all kinds of things, including terrorism. ‘’The time young people spend on social media and the sometimes unmoderated display of violence here, likely plays a role in the increase of radicalisation among young people.’’ When it comes to thwarting attacks, he said European intelligence services are generally in a better position than they were 10 years ago as their co-operation has increased significantly. He said the authorities in Vienna received “a tip from a foreign state” which shows “that co-operation is robust and lasting”. Vladimir Voronkov, head of the UN Office of Counter-Terrorism, has also highlighted the danger posed by ISIS-K to Europe. “The group is considered the greatest external terrorist threat to the continent,” he said. ISIS-K carried out an attack <a href="https://www.thenationalnews.com/news/europe/2024/03/28/terror-threat-upgrade-shows-one-attack-wont-be-enough-for-isis/" target="_blank">on a concert hall in Moscow</a> in March which killed 137 people. Mr Bosscher said that ISIS-K “are the most visible and able to carry out international attacks and want to become the main Islamist terrorist organisation”. The Vienna plot drew comparisons to a suicide bomb attack in 2017 at an Ariana Grande concert in Manchester, England, that killed 22 people. The bomb detonated at the end of Grande’s concert as thousands of young fans were leaving, becoming the deadliest extremist attack in the United Kingdom in recent years. Swift's three concerts in Vienna, due to start on Thursday and for which all 65,000 tickets were sold, <a href="https://www.thenationalnews.com/arts-culture/music-stage/2024/08/08/taylor-swift-vienna-concert-dubai/" target="_blank">were cancelled.</a> The singer is still set to travel to London’s Wembley Stadium for five concerts between August 15 and 20 to close the European leg of her record-setting Eras Tour. London Mayor Sadiq Khan said that while he understood Vienna’s reasons for cancelling “we’re going to carry on”.