Main suspect, a 19-year-old Austrian, said to have pledged oath of allegiance to Islamic State group ‘in recent weeks’

Austrian authorities have arrested a 19-year-old man for allegedly planning an Islamist attack in the Vienna region, in connection with concerts by US star Taylor Swift later this week.

The man, who had pledged his allegiance to the Islamic State (IS) group “in recent weeks”, was detained in Lower Austria about an hour from the capital early on Wednesday, Austria’s top security chief, Franz Ruf, told a press conference.

“We have established corresponding preparatory acts and also that there is a focus of the 19-year-old perpetrator on the Taylor Swift concerts in Vienna,” Ruf said.

The man, an Austrian citizen, is believed to have become radicalised on the internet. Ruf said that chemical substances had been seized at the suspect’s home and were being evaluated.

A second person believed to have been in contact with the suspect was arrested in Vienna.