Specific details about the security breach have not been confirmed by the band.
However, the Irish Mirror (citing Swedish media outlet Expressen) reports that police were searching for a man who was allegedly armed with a gun and threatening another person in the audience. Billboard reached out to U2's representatives, who stated that all the information they have at this time is on the band's website.
Read the full note from U2 below:
“Due to a security breach, Stockholm's The Globen evacuated the audience from the building this evening.
As the breach has not been resolved quickly and as audience safety is paramount, the police have advised The Globen and Live Nation that they have no option but to postpone tonight's show, to a rescheduled date of Tuesday 22nd September.
All tickets from Sunday 20th September are valid for Tuesday 22nd September.
The organizers apologize for the inconvenience caused and thank the audience for their understanding. Their safety is the priority.”