A man has been stabbed in the neck after asking a group of teenagers to stop throwing snowballs.
South Yorkshire Police said the 19-year-old victim challenged the youths for throwing snowballs "aggressively" at people and at passing cars.
The attack took place between 8pm and 8.15pm on Thursday December 2 near a food shop in the Upperthorpe area of Sheffield.
The injured man required surgery but was later allowed home.
A police spokesman said he was kicked, punched and stabbed in the neck with a sharp object, possibly a broken bottle, by a group of teenagers
Another 19-year-old, the man's friend, the man's friend, required stitches for a cut to his forehead and bruising to his face.
The group comprised about 15 males, all said to Asian or mixed race and aged between 15 and 20.
Chief Inspector Andy Male said: "We appreciate that when there is a fall of snow people will play around and throw snowballs, but I would like them to think about the effect of their actions on others.
"The fact this group decided to assault a member of the public for challenging their behaviour is not acceptable".