After a weekend of criminal behavior around Chicago’s Mag Mile city leaders and officials are cracking down on those who cause trouble.

The alderman of the 2nd Ward, Brian Hopkins, says this weekend there were several hours where it was just mayhem around his ward.

Police arrested 21 people, including 20 juveniles.

There was a video posted on Monday on YouTube showing a security guard being assaulted by two people outside the Gold Coast McDonald's on Chicago and State Street.

As the scuffle continues, you see one of the attackers picks up what appears to be a can of pepper spray and points it at the security guard.

Immediately, the security guard pulls out his gun. No shots were fired, but that's what it took to send his attackers away.

Right now, it's unclear what lead to the incident and if it's even related to the weekend havoc.

Alderman Hopkins says this is a serious problem that needs to end and if it means arresting individuals causing trouble they will.

The Water Tower Place issued a policy where teens must be accompanied by an adult after 4 p.m. on Fridays and Saturdays.