A teenager's jaw and teeth were broken when he was attacked in the car park at Dunstable Town Football Club's ground at Creasey Park.
The assault happened at 1.10am on Saturday, March 13, when the victim, who had been at the clubhouse, started walking home with a small group of friends.
They were approached by a gang of about 10 youths, some described as white and others as black, who surrounded the teenager before hitting him in the face.
The attackers ran off and the 17-year-old victim was unable to describe them to police.
Det Sgt Jo Dyer, of Dunstable CID, said: "This was an unprovoked attack. He has undergone emergency surgery, but it has left him and his family and friends deeply shocked.
"If you know who assaulted him or why, please contact the police."
You can call Det Sgt Dyer on 01582 473273.
www.bedfordshire.police.ukwww.crimestoppers-uk.org