The nation of Norway was on the verge of declaring a state of emergency, thanks to Justin Bieber.

Chaos broke out after the teen idol told fans he was giving a free concert.   

Bieber tweeted: "At 920 2nite Im going to do a free show 4 u the fans at the opera house here in Oslo."

A mob scene ensued. Tens of thousands of screaming girls flooded the streets. 49 girls were trampled and injured. But the show went on.

After the concert, Bieber escaped by water, hopping aboard a boat to flee the frenzy.

He personally shot a video of screaming fans following in their little speed boats.

"The fans followed us in a new way" he wrote.