A Safeway security guard was struck with an unknown metal object after confronting a man who stole a box of wine from the store Tuesday night.
The suspect went straight to the liquor aisle upon entering the Safeway on Powell and Bay streets and took a box of wine, police said.
The security guard followed the suspect as he left the store around 8 p.m. When he confronted the man, the suspect hit him in the back of the neck with an unidentified metal weapon before fleeing the scene.
The guard was taken to San Francisco General Hospital to treat his injuries.
Police and still searching for the suspect.