(CBS) – Police say women escorts are the target of a recent crime spree on Chicago’s Northwest Side.

The women are lured to abandoned buildings, where they are robbed and sometimes sexually assaulted, CBS 2’s Brad Edwards reports.

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Two young men, possibly teens, are working as a team to ambush the victims, police say.

“My concern is that they will become more violent. It’s already escalating, I feel,” Chicago Police Detective Susan Ruck says.

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Five incidents have occurred three police districts in the past month, most recently on Monday. There could be additional crimes that haven’t been reported, says Ruck, who asks victims to come forward.

Tips and information can be called in to (312) 744-8200.

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