UPDATED 06/06/11 8:53 a.m.
CHICAGO (CBS) -- At least five teens have been charged in a string of mob-style attacks in the bustling Streeterville neighborhood over the weekend.
Chicago's acting police superintendent says people need to stay alert but "nobody should be afraid" following incidents this past weekend.
"Our reaction to it has been quick, it's been swift, and it's been very effective," Police Supt. Garry McCarthy said. "I don't believe that it's going to be something that we need to worry about long-term. We have to knock this out. We have to knock it out quickly — and that's what we're doing."
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As CBS 2's Susanna Song reports, the attacks are now raising fears of flash mobs.
The man had parked on the 300 block of East Chicago Avenue across the street from Northwestern's Wieboldt Hall when a group of 15 to 20 teens and young men 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.
"It was concerning, obviously, because my wife had been walking the dog here an hour after that," said Dr. Wayne Soong of nearby Northwestern Memorial Hospital.
The victim was treated on the scene by Chicago Fire Department paramedics.
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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.
On Sunday night, with the help of one of the victims, police spotted and arrested some of the teens responsible.
Three of the teens – Dvonte Sikes, 17, of the 7500 block of South Normal Avenue; Travolus Pickett, 17, of the 8400 block of South Dorchester avenue; and Derodte Wright, 18, of the 3500 block of South State Street – have been charged as adults with felony robbery and mob action.
Sikes' bond was set at $250,000. Pickett's at $300,000 and Wright's at $200,000.
Two other 16-year-olds were also charged.
A police source said a sixth suspect, also a male juvenile in his teens, was charged with mob action in connection with the attacks.
The attacks are raising serious concerns about safety in the busy, Manhattan-like neighborhood just north of downtown.
"It's a popular part of the city. It draws a lot of people from other parts of the city," said neighbor Danny Pho. "From what I understand, it's not the first time some sort of incident like this has happened."
A man walking his dog early Monday morning said he is so disturbed by the flash mob attacks that he is planning on moving out of the neighborhood. He said the latest incidents are not isolated, and the flash mobs have been hitting the area for several months.
He also said police do not patrol the neighborhood very often. Much of Streeterville is patrolled by Northwestern University police, as well as Near North District Chicago Police.
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Chicago Police made "in excess of 20 arrests" in connection with the weekend incidents, McCarthy told the Sun-Times on Monday.
Speaking during a break at his City Council confirmation hearing, McCarthy pointed to the arrests as proof there are enough officers downtown, that department staffing and deployment strategy is working, and that shoppers, employees and residents have nothing to fear.
Asked whether tourists and people wanting to enjoy the lakefront should be concerned, McCarthy said, "No. No. But, what we do have to do is have awareness. You don't want to walk in dark areas by yourself after having a fight at a bar with a friend and you're going home. We still have to pay attention to common-sense things to do. We have to be aware. That's the nature of the world today. But, nobody should be afraid of this."
The Sun-Times Media Wire contributed to this report.
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