Disturbing footage of a thug punching what appears to be a random passer-by in the face has sparked fury online.
The video was shared on social media over the weekend and was reportedly filmed in the Swedish city of Malmo.
It shows a young man walking backwards on a pavement towards a woman who is passing by.
Without any warning, he punches her square in the face. A shriek of laughter erupts from behind the camera as the victim falls to the ground.
She appears to be momentarily knocked out before then sitting up and seemingly crying in pain as her attacker runs away to more laughter.
Police in Malmo have not yet released an official statement on the footage, which bears a disturbing similarity to the “Happy Slapping” trend that originated in the UK in 2005.
The shocking fad involved people attacking a victim simply for the purpose of filming an assault.
The clip has since gone viral, sparking fury among viewers.
“That is absolutely disgusting,” one user wrote.
Another commented: “This is barbaric behaviour, lock them up.”
Many others called for Swedes to organise vigilante groups to stamp out the unprovoked assault.
It is not the first time a man has been filmed sucker-punching a pedestrian in recent weeks.
Daniel Biggs was recently filmed punching an elderly passerby in the face in front of a fire station.
But he quickly got served an instant dose of karma when firemen chased after him and pinned him to the ground until police arrived.
Biggs, of Brooklyn, was charged with assault, menacing, harassment and attempted assault.