The robbery was reported at about 3 p.m. Monday in the 200 block of Grant Avenue between Post and Sutter streets.
Three suspects -- a woman and two men -- entered the business with a handgun and forced two women, ages 26 and 32, into a closet, according to police.
One of the victims got into a struggle with one of the suspects, a woman in her mid-20s, and suffered minor injuries that left a mark on her neck, police said.
The suspects eventually took clothing and cash before fleeing. Police did not specify which store was robbed.
The suspects were still at large this morning, police said.
Anyone with information about the robbery is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.