A member of Occupy SF was critically injured in a stabbing by a visitor to the group's encampment along San Francisco's Market Street on Sunday night, police and Occupy officials said Monday.

The 28-year-old man was stabbed in the chest around 10:40 p.m. Sunday in the 100 block of Market Street, police spokesman Officer Albie Esparza said.

A number of "reoccupiers" from Occupy SF have been camping in front of the Federal Reserve Bank of San Francisco at 101 Market St. since last month, according to the Occupy SF website.

A statement from the group Monday confirmed that a male Occupy member was stabbed and is recovering in the hospital.

Esparza said the victim had gotten into an argument with the suspect over the whereabouts of a camera. The altercation turned physical and the victim was stabbed in the chest.

He was taken to San Francisco General Hospital to be treated for his injuries, which were considered life-threatening, Esparza said.

The group said the stabbing suspect was not a member of Occupy.

"This man had visited the 101 site several times over the past week but is not known by the protest members. After the incident the unknown male left on foot before people in the vicinity fully recognized what had occurred," the group said in the statement.

The suspect, who has yet to be found, is described as a white man between 20 and 25 years old who is about 5 feet 5 inches tall, weighs about 135 pounds and has blond hair and blue eyes. He was last seen wearing a dark-colored beanie, a dark-colored puffy jacket and black-framed glasses, Esparza said.

Anyone with information about the case was encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.