At 8:45 p.m. on Friday, two suspects, a 22-year-old man and a 13-year-old, approached two men on 24th and Treat streets and snatched their bicycles, according to police.
One of the suspects was arrested but the other fled the scene on the bicycle, police said.
A man was robbed at gunpoint on South Van Ness Avenue and 18th Street shortly before 1 a.m. on Saturday, police said.
The victim, a 28-year-old man, had been walking along South Van Ness Avenue and then headed west on 18th Street toward Capp, through a parking lot. The suspect, a 25-year-old man, got out of a black Cadillac and approached the victim, demanding his property while showing him a handgun.
The victim threw his wallet on the sidewalk and ran away, according to police.
A 28-year-old man was stabbed on 16th and Julian at 1:12 a.m. on Sunday, police said.
Three suspects, described as men in their 20s, jumped the victim from behind, then cut and stabbed him.
The three suspects fled on foot. The victim suffered cuts to his face and arm and was taken to the hospital.
A 35-year-old woman was the victim of a carjacking on Dearborn between 17th and 18th streets at 1:10 a.m. on Sunday, police said.
Two men driving a 1980s dark-colored sedan stopped near the victim, who was inside her car. One of the suspects demanded her earrings and ripped the necklace from her neck.
One the suspects then pulled the victim out of her vehicle and brandished a firearm. The suspect got into the vehicle and drove away; the second suspect followed in another vehicle.