Police rushed to the area, where they found a large crowd gathered, with six people dead in the street and another 12 injured.
“We had a large crowd in the area. We don’t know if it was part of a club or an event,” Chief Lester said.
The Sacramento Fire Department who transported seven people to hospital said four were suffering from critical injuries.
Emergency crews confirmed that remaining gunshot victims either drove themselves to hospitals, or were driven.
In a statement released by police they said "at least one firearm" had been recovered from the tragic scene.
"We're asking for the public's help in helping us to identify the suspects in this," Ms Lester said.
Sacramento mayor, Darrell Steinberg, told reporters the situation was overwhelming, and that words could not express his "shock and sadness".
“The numbers of dead and wounded are difficult to comprehend,” he said on Twitter.
"We await more information about exactly what transpired in this tragic incident.
“Rising gun violence is the scourge of our city, state and nation, and I support all actions to reduce it,” he said.
This is the third mass casualty shooting this year in the United States.
More to come.
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