Police received multiple calls of shots fired near the corner of 96th Avenue and Olive Street at 6:08 p.m. and the city's ShotSpotter system alerted officers to a hail of gunfire in the area, police spokeswoman Officer Johnna Watson said.
Responding officers found multiple victims in the sidewalk area there, and more victims turned up at a hospital a short time later.
A 29-year-old man and a 31-year-old man were left in critical condition. Five other men -- two 29-year-olds, a 28-year-old, a 27-year-old and a 23-year-old -- are expected to survive their injuries, Watson said.
Police have blocked off streets and are still processing evidence tonight to determine who shot the seven victims and why.
Watson said police believe that people in the area witnessed the shooting and are urging anyone with information to contact Oakland police.