SAN FRANCISCO -- San Francisco police are investigating a strange case Wednesday night after a woman was found gagged inside a medical building suffering from serious injuries. The victim remains hospitalized and is fighting for her life.

Police say the very unusual and serious crime occurred in one of the medical facilities operated by California Pacific Medical Center on the 3600 block of California Street in the upscale Laurel Viliage neighborhood at around 8 p.m. Tuesday night.

This area is filled with small businesses and medical buildings. Police say an Asian female in her 60s was found inside a room with a washcloth stuffed in her mouth, suffering from life threatening injuries.

Police say the victim was taken to California Medical Center on Buchanan Street, but the deputy chief in charge of investigations refused to tell us exactly what happened.

"Right now, we're at a very critical point in the investigation. Even though I want the public to know that there is no issue of public safety to them, it's very hard for me to comment on it without compromising the case," said San Francisco Deputy Police Chief David Shinn. "We cannot compromise this case."

Police declined to say what the motive for the attack was or the nature of the victim's injuries. Nor would police say whether the victim was a patient or employee of the medical center.

A hospital spokesman told us the unidentified woman is in critical condition. Police say they hope to release more details on the crime Thursday.