Police spokesman Sgt. Troy Dangerfield said there was no immediate information linking the robberies, which occurred throughout the city. No arrests were made.
In the first robbery, a 29-year-old woman was walking on Rose Street near Laguna Street in Hayes Valley at about 7:45 p.m. when two men in their 20s tried to grab her purse, police said.
When she resisted, she was pushed up against a wall and one of the suspects pointed a gun at her. The suspects took her purse and fled.
At 11:25 p.m., a 28-year-old woman walking on 18th Avenue near Anza Street in the Richmond District was approached by two men in their late teens or early 20s, according to police. One pointed a gun at her and robbed her of a cell phone.
At about 11:30 p.m., a 51-year-old man was robbed in front of his house in the 1600 block of Quesada Avenue in the Bayview District, police said. In that case, a man in his early 20s brandished a handgun, robbed the man of cash, and fled in a car.
About 45 minutes later, a 52-year-old man and a 41-year-old woman walking in the 400 block of Pacific Avenue in the Financial District were approached by a car containing multiple men in their 30s, according to police. One of the suspects got out, showed a handgun and robbed the two, and then got back in the car and drove off.
At about the same time, an armed robbery was reported in the 200 block of Leavenworth Street in the Tenderloin, police said. Two suspects, one a man in his 20s, pulled up to a 34-year-old man in a van and asked if he had any marijuana. When the man said he didn't, one suspect climbed out of the van, struck the victim with a gun and stole cash from him.