SAN DIEGO (CNS) - Authorities are investigating a sexual assault in the City Heights area of San Diego Monday.



The attack was 6:30 p.m. Saturday, in an alley near 3500 Van Dyke Ave, according to San Diego police.



A woman went in the alley to dump her trash in the dumpster at the south end of the parking lot and was grabbed there by her assailant, police said.



The suspect grabbed the woman from behind, using one hand to wrap around the victim's neck while in the other hand he held a knife that he put up to her face, police reported. The suspect then forced the woman to walk a short distance away where he sexually assaulted her and then ran from the alley.



The man was described as black, 25 to 35 years old and about 6 feet tall with an average build, according to police. He had long dreadlocks which came down to his chest, a well-groomed goatee and an earring in his left ear. The victim said he smelled of cigarette smoke and had a deep voice.



He was wearing a black sweatshirt, black pants and black shoes, police reported.



This is the second sexual assault reported in the San Diego area this weekend. Today a woman also was assaulted in Ocean Beach and both suspects remain at large.



Anyone with information on these attacks was asked to call the SDPD's Sex Crimes unit at (619) 531-2210. Tipsters can also call Crime Stoppers at (888) 580-8477.