SAN FRANCISCO - Four people were killed and several others wounded in a shooting at Halloween house party in Orinda, Northern California, Thursday night, local TV network KTVU reported early Friday.

Police in Orinda, a city in Contra Costa County, Northern California, tweeted that they are investigating a mass shooting that took place at a private party hosted at an AirBNB rental around 11 pm (0600 GMT Friday) along the 100 block of Lucille Way near Highway 24.

"Orinda homicide update - four fatalities, several injuries," Contra Costa police@cocosopio said in the tweet.