According to police, 18 armed robberies occurred between Friday night and Sunday night.
Police spokesman Sgt. Wilfred Williams acknowledged the amount was "unusual" but would not say if police believed any of the robberies were connected.
Most of the suspects were armed with guns, though some had knives, according to police.
Some of the areas where robberies were reported include the Richmond District, Visitacion Valley, the Western Addition, the Mission District, Eureka Valley, the Bayview District, the Sunset District, Hayes Valley, the Fisherman's Wharf area, and San Francisco's Ferry Building on the Embarcadero. Most took place at night or in the early morning hours. Some of the victims reported being pistol-whipped.
In only two incidences were the robbers unsuccessful. Only one arrest was reported.
Williams said police would be responding to the robberies, but he declined to give specifics on enforcement operations, citing active investigations.
"Captains will be working at addressing the situation in those areas where the robberies occurred," Williams said.
Williams also offered advice to victims confronted by would-be robbers.
"It's better not to resist and to notify the police," Williams said.
"If they come attempting to rob you, it's better to give up whatever it is that they're coming to get, instead of trying to fight back, because you don't know what they might have," he said.