“After technicians inspected it, the suspected offence was renamed from planning of public devastation to attempted murder,” said Kjell Lindgren, spokesman at the Stockholm police.
The explosives were found in connection with a veterans match at the new arena involving Stockholm club Djurgården.
Djurgården has called a crisis meeting on Friday with the police and rivals Hammarby, the club with whom Djurgården are to share the stadium when it formally opens in the autumn.
According to a report in the Aftonbladet daily the bomb could have links to the match and the issue of which club should have the formal right to open the stadium.
“We are not naive, we knew that there were strong emotions over us playing at the stadium,” said Gunnar Gidefeldt at Djurgården to the newspaper.
The official opening of the stadium is slated for August 24th with a concert featuring Kent, Robyn and Lars Winnerbäck. However several football matches have been scheduled for the première week 20-27th July.
Hammarby is due to be first up hosting Örgryte, followed by Djurgården against Norrköping a day later.
Hammarby fans have made their opposition known to the Djurgården veterans match which some felt was a clandestine inauguration of the 30,000 seater arena.
“This was a test-event. We didn’t want to inaugurate the stadium,” said Gunnar Gidefeldt to Aftonbladet.
Thursday’s match was cancelled after the bomb find and the stadium was cordoned off as police searched the area around the stadium for further devices.