A 53-year-old man suffered life-threatening injuries Monday night when a woman stabbed him in the back repeatedly in Mission Bay, according to police.

San Francisco police are investigating the stabbing at Terry Francois Boulevard and Mariposa Street as an “apparent unprovoked attack,” police said.

The man was taken to a hospital after being stabbed at around 8:27 p.m. His assailant, a 53-year-old woman, was also taken to the hospital with injuries and arrested.

Police have not released her name or further details.

The stabbing was not the only incident that left a man with serious injuries on Monday.

Hours after the Mission Bay knife attack, a 35-year-old was found unconscious near the Ferry Building.

Evidence at the scene suggested the man had been robbed near Don Chee Way and Steuart Street at around 10:15 p.m, police said.

The man appeared to have been attacked with a bottle, according to police. His wallet and cellphone had also been stolen.

The victim was taken to a local hospital with life-threatening injuries.

A suspect has not been identified in the case.

mbarba@sfexaminer.com