A 10-year-old boy was riding an Muni bus in the Bayview when he was stabbed twice Thursday, allegedly by a 27-year-old woman.

Other passengers on the bus near Palou Avenue and Jennings Street grabbed the suspected knife-wielder, later identified by police as Sharinna Beoncia Grady of San Francisco, and took the blade away from her, Officer Albie Esparza said.

The altercation unfolded when Grady began arguing with the boy, police said. At some point, she allegedly stabbed him with a folding knife in the shoulder and hand and scraped his cheek. He was taken to San Francisco General Hospital and is expected to survive.

Grady’s relationship to the boy is unclear, but Esparza said they know one another.

Grady was arrested around 3:05 p.m. and booked into County Jail on suspicion of felony attempted murder and felony assault with force likely to cause great bodily injury, authorities said.

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