Police would only confirm that they responded to a battery in progress. They would not confirm what happened exactly or how many people were involved.
As police investigate, witnesses say the incident may have started as a robbery at the lakefront. The robbery victims then chased the suspects but were over powered when they caught up with a couple of the suspects, according to witnesses.
ABC7 talked with one man who says he saw the scene unfold near Michigan Avenue as he left work.
"That's when we dropped our uniforms and I dropped my book bag and tried to help. The kid gets back up. And they chase the guy in front of Potbelly's and that's where it ended. They beat him pretty bad but he got up all right. He was really traumatized since it was his first time getting jumped on. So it's really pathetic that 15 have to jump two," said Cory Bynum, witness.
There are reports that as many as five young men may have been arrested, although police would not confirm that.
A man was attacked in a mob attack Saturday night in Streeterville. Seven were arrested after that attack.
Residents are advised to be careful of their surroundings and take care when they take out their wallet.