CHICAGO (WLS) -- Chicago police have sent out a safety alert about burglars posing as utility workers sneaking their way into homes.Once the burglars are inside, they steal the victim's property, police said.The first incident occurred at about 3:15 p.m. on Jan. 5 in the 5300-block of South California Avenue in the Gage Park neighborhood.Three days later, they struck at about 1:50 p.m. in the 2500-block of South Normal Avenue in the Bridgeport neighborhood.On Jan. 10 at about 3 p.m., they got into a home in the 1800-block of West 34th Street McKinley Park neighborhood."He said, 'Don't close the door. Don't close the door. Just one minute.' They tell me to go downstairs, open the water," said victim Chu Seto Dea, of Bridgeport.She said she was taken down into the basement where the fake water department employee pretended to work on the pipes, when the man's accomplices came inside and robbed her."They took my charge card, my ID card and my money," she said.Police say there have at least four similar incidents in the last month that all appear to be related - three in the McKinley Park/Bridgeport area, and one more in Gage Park. All took place in the middle of the day."All the victims are up in age. They're a little more gullible. They're a little more vulnerable," said Det. David Matuel, 9th District, Chicago police. "If they're not being let in, they'll say there is an impeding danger, they've got to come in and check."So far, the burglaries have all targeted immigrant communities. Twelfth Ward Alderman George Cardenas believes this is intentional and says there's already even been one case of someone pretending to be with his office."They know what they're doing. They've done their homework," Cardenas said. "They'll say, 'I'm from the alderman's office. Can you open up? Can we talk about this candidate?' Make sure you verify. You ask questions. You ask for people's ID's.""Ever since over the summer, we've been hearing a couple things about that and it's really strange because McKinley Park is usually a very calm area. I have been living here for at least 15 years and nothing ever happens here, so for something like that to be happening, it's very frightening to be honest," said McKinley Park resident Monica Becerra."I don't like to answer my door anymore to be honest with you. I won't if I don't feel comfortable," said McKinley Park resident Liz Villarreal.In the most recent burglary at about 1:45 p.m. Saturday, they hit a home in the 1300-block of West Fuller Street in the Bridgeport neighborhood."We're a small knit community and normally we do hear if anything is happening and so to hear that happened on my block.I'm really surprised," said Bridgeport resident Abby Castro.Rinn Boyer said police came to her house as they canvassed the area."It's just you realize you're vulnerable I guess and there's nothing you can do about except for try not to think about it and hope that you're not the target," Boyer said.So far, police have not released detailed descriptions of the suspects, but police said they seem to be working in a group of three.Anyone with information is asked to contact Area Central detectives at (312) 747-8382.