About 7:30 p.m. Saturday, the teenagers attacked two men, 28 and 26 years old, and a 29-year-old woman at the Chicago and State station at 800 North State Street, according to Chicago police. All three suffered bruising and lacerations on their faces and bodies and were treated on the scene by Chicago Fire Department paramedics.
Trains were stopped for about two hours after the attack while police investigated.
Earlier Saturday, two teenagers were arrested at the North Riverside Park Mall in the western suburbs after a group of teenagers caused a disturbance at about 5 p.m. The mall closed early as a result.
The disturbances spilled over to the Water Tower Place in downtown Chicago.