Two men are said to have been critically injured in the shooting in the south side area of the city. The other three are in serious condition.
'It does not appear to be that these (people injured) were students at the school and it appears it is possibly gang related,' Chicago police officer Amina Greer told wire services.
Witnesses told police the gunmen drove up in a sport utility vehicle and fired into a crowd leaving the game at Dunbar high school at about 7.45pm.
'A girl started screaming and then we just started hearing shots,' Robert McCallum told CBS2 news.
'I was the first to jump on the ground because they started shooting our way and everybody piled up on me. Man, it was crazy.'
Police were combing the city's snow-bound streets for the shooters but made no immediate arrests.
