A man who was snapping photographs at San Francisco City Hall just before midnight Monday was pistol-whipped and robbed of his camera, police said.
Two juveniles struck the 45-year-old man over the head several times at Polk and Grove streets.
They fled in a white 1997 Hyundai, police said. The victim pursued the suspects and was able to provide police a description of the vehicle. Two teenagers ages 16 and 17 were subsequently arrested, police said.
The identities of the suspects will not be released because they are minors.
The victim, who suffered head lacerations, was in stable condition at San Francisco General Hospital, police said Tuesday.