A 33-year-old man wearing a bullet-proof vest was shot 16 times Sunday morning while walking through the Tenderloin neighborhood, police said.

At about 3:15 a.m., the man, who is a resident of Oakland, was walking down the 300 block of Ellis Street when he was shot 16 times -- and once in the face, police said.

The man was taken to San Francisco General Hospital with life-threatening injuries, said Office Samson Chan.

Chan said it is still too soon to say whether the shooting was gang-related, but the fact that the man was wearing a bullet-proof vest is certainly “unusual,” Chan said.

“It certainly could be gang-related or it could be drug-related,” Chan said.