CHICAGO - Chicago police have warned residents in the Kenwood neighborhood, where President Obama still maintains a home, that robbers have held up victims six times on the same block in one week and committed another robbery nearby, reports CBS Chicago.

Police said there were six robberies on the 4700 block of South Ellis Avenue in the span of a week, from June 1 to June 7. A seventh robbery was carried out a block away on the 900 block of East 47th Street on June 4, according to the station.

A community alert issued by Wentworth District police says a group of three robbers threatened the victims and then robbed them on the street.

Angela Washington, who lives on the block, said it's sad, because they're only half a mile from President Barack Obama's home, on the 5000 block of South Greenwood Avenue.

"It's a lot of hard-working people in this neighborhood, and we work hard for our stuff. You know, I'm up early, going to go to work," she told the station.

Six of the robberies happened overnight between 8:30 p.m. and 4:45 a.m. One holdup happened at 4:30 p.m.

Police had only vague descriptions of the suspects: Two black males and one white female, all in their late teens to late 20s.

CBS Chicago has learned police may be working on the theory that the female suspect is acting as "bait" in setting up the robbery victim.

Sources tell the station the female in the robbery group has been soliciting men on her Facebook page with the promise of sex. Once the victims show up at 47th and Ellis, her two accomplices rob them.

Sources say one of the victims said he was set up via that scam. The victims are not necessarily from Kenwood.

No arrests have been made.