Chemical substances have been found at the home of a 19-year-old Austrian suspected of planning an attack on forthcoming Taylor Swift concerts in Vienna, Austria’s intelligence chief has said.

Franz Ruf, public security director at Austria’s Interior Ministry, told public broadcaster ORF’s Oe1 programme on Thursday that, following the arrest of two suspects earlier this week, investigators found chemical substances and technical devices at the teenage suspect’s house and these are now being evaluated.

He added that, just a few weeks ago, the suspect had uploaded an oath of allegiance to the current leader of the Islamic State group militia to an internet account.

The cancellations of the concerts devastated Swifties across the globe, many of whom had spent thousands of euros on travel and accommodation in Austria’s expensive capital city for the US singer’s sold-out Eras Tour shows on Thursday, Friday and Saturday at the Ernst Happel Stadium.

The venue was deserted on Thursday morning apart from media filming outside.