A third suspect has been arrested in Vienna over a plot to attack a Taylor Swift concert, Austria's interior minister said on Friday. 

The announcement that another teenager was in custody came a day after two arrests had been made in connection with the threat that prompted organizers to cancel a trio of concerts planned for the Austrian capital.

Suspect allegedly swore allegiance to IS

Interior Minister Gerhard Karner said that the latest arrest concerned an 18-year-old. The main suspect was 19, and a 17-year-old has also been detained.

Karner said that the main suspect and the man arrested on Friday had sworn "oaths of allegiance" to the "Islamic State" (IS) terror group.

"He had been in contact with the main perpetrator, but is not directly connected to the attack plans," Karner told the Associated Press. "But, as was found out a few days ago, he took an oath of allegiance specifically to the IS on August 6."

The main perpetrator was also found to have researched bomb-making online and read materials relating to the al-Qaeda terrorist network.

Officials said he had confessed to planning the attack beginning in July, and had wanted to "kill as many people as possible outside the concert venue" with explosives and knives.

UK will go ahead with Taylor Swift concerts

The cancellation of three shows for Swift's highly lucrative "Eras" tour prompted major disappointment in Vienna.

"I understand very well that those who wanted to experience the concert live are very sad," Austrian Chancellor Karl Nehammer told reporters Thursday.

"Moms and dads are looking after their daughters and sons, who were full of enthusiasm and anticipation for this concert. But it's also important that in such serious moments as now, it's inevitable that safety comes first."

London Mayor Sadiq Khan said that there is no plan to cancel Swift's upcoming concerts in the UK, though the country has not forgotten a 2017 attack on an Ariana Grande concert in Manchester that left 22 people dead.

Recent Swift concerts in Germany drew massive crowdsbut also saw the arrest of an alleged stalker of the US pop star.

es/ab (AP, AFP)