Updated 06/05/11 - 12:50 p.m.
CHICAGO (WBBM) -- Police said at least two people were attacked by criminal "flash mobs" in the Streeterville neighborhood on Saturday night.
The first attack happened around 8:25 p.m. Saturday when a man was attacked after parking his motor scooter near the Northwestern University campus in Streeterville.
The man had parked on the 300 block of East Chicago Avenue across the street from Wieboldt Hall when a group of 15 to 20 men, all approximately 16 to 20 years old and black, approached him, according to an alert from the university.
One of them threw a baseball at the victim's face and knocked him to the ground, the alert said. Several others from the group punched and hit him several times. The victim tried to protect himself and fought back.
The group eventually fled eastbound toward the lake. Chicago Police and Northwestern University Police responded, and Chicago Police later arrested three members believed to be part of the group on mob action charges, the alert said.
The victim was treated on the scene by Chicago Fire Department paramedics.
The school has issued an alert for student and staff and Chicago Police later arrested three members believed to be part of the group on mob action charges, according to the alert.
Police News Affairs Officer Michael Sullivan said the investigation is ongoing as of Sunday morning and no charges have been filed.
A few minutes after that attack, man riding his bicycle on the lakefront path at 701 N. Lake Shore Dr. was attacked by a group of teenagers, who punched and kicked him and stole his cell phone, sources told WBBM Newsradio 780.
Belmont Area detectives are investigating.
(The Sun-Times Media Wire contributed to this report.)
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