After being kicked, the unidentified victim was dragged through the snow and placed onto a small tree. He tried to run away, but he was caught, and his attackers hung him by his jacket on a tall metal fence.
Police said it happened in the afternoon earlier this month, and at least one witness passed by and did nothing.
"I tried to leave, tried to escape, tried to get out the tree and run away, but even when I did that, when I got out the tree the first time, they attacked me and they caught me again," the victim said.
Six of the seven alleged attackers are the victim's classmates and were arrested at school. They face charges including kidnapping and false imprisonment.
The defendants range in age from 13 to 17.