CHICAGO (WLS) -- Chicago police are warning residents after four women were attacked in the same area of the city's South Side, possibly by a serial rapist.Police said the attacker was armed with a gun. The four attacks happened in Chatham and Greater Grand Crossing over the course of the past two months, with the most recent happening last Friday afternoon."That just makes me really nervous, you know, because that could be me, or my sister, or my grandmother," said Sherelle Alexander, Chatham resident.The first attack occurred at about 5 a.m. on July 12 in the 7600-block of South Evans Avenue. On July 25, at about 5:30 a.m., a woman was attacked in the 7400-block of South Vernon Avenue. Then on August 6, at about midnight, a woman was attacked in the 7400-block of South King Drive. Finally, at about 2 p.m. on Friday, August 23, a woman was attacked in the 7700-block of South Langley Avenue.In each instance, the suspect approached a woman who was alone and lured her into a secluded area, police said. The suspect then pulled out a gun, sexually assaulted the victims, took their property and fled, according to police."We'll be looking out for any bad elements that we'll see," said Brian Collins, Greater Grand Crossing resident. "We need to get him off the streets.""It makes me really on edge to be honest, because the fact that it's so close to home, literally. It's nerve wracking," Alexander said.Police only have a vague description of the attacker, but said he was last seen on Prairie near Marquette Road. Police hope someone in the area saw something that could help the investigation.If you have any information about these attacks, contact Area Central Detectives at 312-747-8380.