Justin Bieber performs live at the Opera House in Oslo, Norway. (GETTY/GALLO)
Justin Bieber fans gather in the harbour on small boats prior to Justin Biebers performance at the Opera House in Oslo, Norway. (GETTY/GALLO)
Justin Bieber performs live at the Opera House in Oslo, Norway. (GETTY/GALLO)
Justin Bieber fans gather prior to his performance at the Opera House in Oslo, Norway. (GETTY/GALLO)
Justin Bieber fans crowd a doorway prior to his performance at the Opera House in Oslo, Norway. (GETTY/GALLO)
Fans chase after Justin Bieber in the harbour in small boats after his performance at the Opera House in Oslo, Norway. (GETTY/GALLO)
Fans chase after Justin Bieber in the harbour in small boats after his performance at the Opera House on May 30, 2012 in Oslo, Norway. (GETTY/GALLO)
Justin Bieber performs live at the Opera House in Oslo, Norway. (GETTY/GALLO)
Justin Bieber fans gather prior to Justin Biebers performance at the Opera House in Oslo, Norway. (GETTY/GALLO)
The young fans ran screaming towards the nearby Royal Christiania Hotel, where Justin was staying. (YOUTUBE)
The police threatened to issue a state of emergency because of the singer's fans. (YOUTUBE)
Justin Bieber performs live at the Opera House in Oslo, Norway. (GETTY/GALLO)