CHICAGO (CBS)—A brawl involving dozens of teenagers broke out near Chicago’s Water Tower Place Tuesday night, prompting a flurry of 911 calls as the mob spread to Chicago Avenue and State Street.

The disturbance grew so large at one point that some businesses in Chicago’s busiest tourist district were forced to shut down, CBS 2’s Jim Williams reports.

“The group is running westbound on Chicago,” one 911 caller is heard saying.

One person who witnessed the fight asked to stay anonymous, but told CBS that a group of about seven teenagers jumped a person walking down Chicago Avenue between Wabash Avenue and Rush Street.

Witnesses reported seeing teenagers and adults fighting at Chicago Avenue and State Street, prompting McDonald’s and Chick-Fil-A to lock up.

In an attempt to control the mob, police barricaded the area with police cruisers and bikes before ushering people toward the trains.

Witness Anton Johnson told CBS the crowd seemed to be cooperating with police.

Police say there have been at least four large disturbances in this popular area this summer. Right after Memorial Day, Superintendent Eddie Johnson explained why officers moved kids toward the Red Line.

“We didn’t force anyone to go anywhere — we directed them,” Johnson said. “You choose to stay here, then that was your choice. But if you choose to leave then we gave you a safe way to leave.”

Two people were arrested Tuesday night for disorderly conduct, police said.