Police are warning residents of a pattern of sex assaults reported in the Park Manor and Chatham neighborhoods on the South Side.

In each of the four incidents, a man approaches a female victim and lures her to a secluded area, Chicago police said. He then shows and handgun and sexually assaults the victim before leaving with their property.

The sex assaults happened:

about 5 a.m. July 12 in the 7600 block of South Evans Avenue;

about 5:30 a.m. July 25 in the 7400 block of South Vernon Avenue;

about 12 a.m. Aug. 6 in the 7400 block of South King Drive; and

about 2 p.m. Aug. 23 in the 7700 block of South Langley Avenue.

The suspect, a man between 20 and 30 years old, was last seen in the area of the 6700 block of South Prairie Avenue, police said.

Anyone with tips is asked to call Area Central detectives at 312-747-8380.