A DEADY game involving random acts of violence against complete strangers has begun trending on social media, prompting calls by one of its victims for tougher penalties against offenders.
The Knockout game involves predominantly young people going up to a complete stranger in the street and hitting them in an attempt to knock them out.
Already police in the US say the 'game' has been linked to several deaths.
In one case, a teacher of 18 years' experience was knocked out in Pittsburgh by a 15-year-old boy.
The boy has since been charged.
"The video speaks for itself, but I don't remember it happening when it happened," James Addlespurger told Channel 4 Action News.
"I was shocked at the whole narrative of it. There were six kids. There was me walking, just normally on my way, and boom came the punch and down I went, straight down with my face falling and hitting the cool concrete.
"I was shocked. I was speechless. I didn't really know what to think," said Addlespurger.
The assault of a Washington DC woman may also be connected to the violent new trend.
The unsuspecting 27-year-old victim was walking in the Columbia Heights neighborhood around 10 p.m., Thursday, when a group of about eight men on bikes came up behind her, NBC Washington reports.
One of the men reached out, punched the woman in the head as hard as he could, and rode away.
In New York, where the unprovoked attacks have targeted Jews, the game is being called anti-Semitic.