An 18-year-old Iraqi national suspected of plotting a terror attack on a Taylor Swift concert has been detained in Austrian capital Vienna.

Police swooped on an address in the city this morning, making the second arrest as part of an investigation into the plot - which could have seen some 20,000 fans targeted outside Vienna's Ernst Happel Stadium.

The Iraqi national is said to have come from the same circle as the main suspect, a 19-year-old Austrian with North Macedonian roots, according to Austria's interior ministry.