ORINDA (CBS SF) — The Contra Costa County Sheriff’s Office and the Orinda Police Department are investigating a Halloween night shooting involving multiple victims in Orinda Thursday, according to authorities.

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The Contra Costa County Sheriff’s Office reported Thursday night the investigation into the shooting was active in the area of Lucille Way and Knickerbocker.

A tweet by the Contra Costa Sheriff’s Office public information officer indicated that multiple people were shot in the incident.

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The incident was first reported at around 11:45 p.m. CHP and other agencies were reportedly being called to the scene due the the size of the crowd at the site.

Police told KPIX 5 they are being overwhelmed by the crowd where the shooting happened, reportedly at a Halloween party.

There was no confirmed information regarding injuries, number of victims or suspects in the shooting as of early Friday morning.

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No other information about the shooting was immediately available from authorities..