One teen had posted a video online confessing to the plot telling people that he had "big plans" (File)
A 19-year-old has been detained in Austria for allegedly plotting to kill people outside a stadium at a Taylor Swift concert, prompting the cancellation of the pop superstar's three shows in Vienna this week.
Two other teenagers have been identified as suspects.
Here is what security officials have said about the three.
THE 19-YEAR-OLD
The Austrian national with North Macedonian roots was arrested in the early hours of Wednesday during a police operation at his home in Ternitz, a town near the Hungarian border.
The teen, who had posted a video online confessing to the plot, quit his job on July 25, telling people that he "had big plans", public security chief Franz Ruf told reporters on Thursday.
The suspect had recently changed his appearance and had been consuming and sharing Islamist propaganda online, security officials said, adding that he had pledged allegiance to Islamic State but also held sympathies for Al Qaeda.
A neighbour told Austrian broadcaster Puls24 that the young man kept himself to himself and that he had grown a "Taliban beard".
During a search of his home, law enforcement authorities secured various substances and tools used for building bombs, as well as Islamic State propaganda, 21,000 euros ($23,000) in counterfeit money, machetes, knives and blank ammunition.
The Kurier newspaper, citing sources familiar with the situation, reported that the suspect had stolen the chemicals from his former workplace, a metal processing company also in Ternitz. Officials did not comment on where he got the chemicals from, adding that this was a focus of their investigation.
THE 17-YEAR-OLD
After initially being tipped off to a single suspect, Austrian investigators came across the other two, including a 17-year-old Austrian national with Turkish-Croatian roots who was arrested in Vienna on Wednesday afternoon.
He had been acting conspicuously in the area of the Ernst Happel Stadium, where Swift's stadium shows had been due to take place on Thursday, Friday and Saturday.
The 17-year-old had been given a job with a company a few days ago that was providing services at the stadium.
The boy, who also appears to have been radicalised and was already known to authorities, had recently broken up with his girlfriend, Ruf said.
He is still to make a statement to police so his exact role in the plot is unclear, but he had extensive contact with the main suspect, officials said.
THE 15-YEAR-OLD
The third and final suspect is an Austrian national with Turkish heritage.
During questioning, the youngster said the main suspect had changed considerably in recent months and had also regularly enquired about devices to ignite explosives, officials said.
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