(CBS) – Someone’s attempting to grab women in south suburban Park Forest, and police are urging residents to be on the lookout.

In the first attack, at about 5:45 p.m. on Tuesday, a man in sunglasses, a black hoodie and gray sweat pants robbed a woman at knifepoint in Winnebago Park and then began to grab her over her bra.

Thursday morning, two attacks occurred.

Police said that at about 8:20 a.m., a man in a brown hoodie grabbed a woman at Westgate Street and Westwood Drive, who broke free. About 40 minutes later, a naked man grabbed a woman by the waist in Shabbona Park.

In all cases, police said, the attacker was black and in his 20s or 30s. It’s unclear if the same man is responsible for all three incidents.

Extra police are watching all three areas. Anyone with information that could help police is asked to call them. The number is 708-748-1309.

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