Police are asking for the public's help locating a man they say sexually assaulted a woman in East Flatbush.

The incident occurred Wednesday inside a stairwell at the victim's apartment building. Police say the 33-year-old woman was entering her building when a man attacked her from behind and sexually assaulted her. They say the suspect stole the victim's cellphone and cash from her purse and fled.

The suspect is described as a black male, approximately 18-25 years old, 5'8" and 155 pounds. Officials say he was last seen wearing a black and white winter hat, a black jacket and camouflage pants. He also had a bicycle.

Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS.