At least 9 are shot in a 'targeted and isolated incident' in San Francisco's Mission District, police say

At least nine people were shot Friday in what police believe was a "targeted and isolated incident" in San Francisco's Mission District neighborhood.

All victims are expected to survive the shooting, which happened while "some sort of block party" was ongoing, San Francisco police Officer Eve Laokwansathitaya said during a news conference.

At least five of the victims were hospitalized, according to Santiago Lerma, a legislative aide to a San Francisco Board of Supervisors member. One of the five was undergoing surgery as of Friday night while four people were treated for minor injuries, Lerma told CNN affiliate KPIX at the scene.

Police officers were called to the Mission District around 9 p.m. local time.

"When officers arrived on scene they located multiple victims suffering from gunshot wounds," police said in a statement. "Officers summoned medics to the scene to treat and transport the victims to local area hospitals."

No arrests were immediately reported by authorities.

The Mission District, better known as The Mission, is a large and diverse neighborhood often known for its historic architecture in the east-central portion of San Francisco.