CNN  — 

Four people were killed in a shooting at a house party Thursday night in the San Francisco Bay Area, according to police.

At least four people were injured in the shooting in Orinda, California, said Police Chief David Cook. More than 100 people were at the party, according to police.

Police told CNN affiliate KPIX they were “overwhelmed” by the size of the crowd at the house where the shooting took place. Other law enforcement agencies responded to the scene, including the Contra Costa County Sheriff’s Office.

Three people were pronounced dead at the house, and another died at the hospital, according to the sheriff’s office.

It was unclear how many victims were injured, since some were taken to the hospital by ambulance and others drove themselves, the sheriff’s office said.

The shooting happened at an Airbnb rental which specifically prohibited parties. Airbnb released a statement condemning the shooting.

“We are horrified by this tragedy and are in close communication with Chief David Cook of Orinda Police to offer our support with his investigation into who committed this senseless violence,” Airbnb said in a statement. “Additionally, we have taken action to ban the booking guest from our platform. Our thoughts are with the loved ones of the victims of this abhorrent act as well as the neighbors of the home.”

The sheriff’s office did not say whether anyone had been arrested. Orinda is a suburb east of Berkeley in the Bay Area.

CNN’s Cheri Mossburg contributed to this report.