Officers responded to a report of a sexual assault near 14th Street and Broadway at about 1 a.m., according to Oakland police.
The victim told police that she was grabbed from behind by two men who took her to a nearby secluded area and raped her at gunpoint, police said.
The suspects were described as black men between 18 and 25 years old, wearing black hoodies and dark jeans.
One of the men spoke in a low voice and carried a handgun.
Anyone with information about the assault is asked to contact the Oakland police youth and family services division at (510) 238-3641 or the anonymous tip line at (510) 637-0298.