Ten people were shot, four fatally, during a family's backyard gathering in Fresno, California, on Sunday (US time).
Fresno police Lt. Bill Dooley says the "mass casualty shooting" took place about 6pm Sunday on the city's southeast side.
Dooley says there was a party in the backyard of a home to watch a football game when the shooting suspects sneaked in and fired into the crowd.
Authorities have not released a total for the number of people killed.
"Officers arrived on scene – what we found were several individuals deceased in the backyard," Dooley told local media outlets at the scene on the 5300 block of East Lamona Avenue.