Four people have been killed and six more wounded after "unknown suspects" sneaked into a garden party in California and fired into a crowd.
The shooting took place about 6pm local time as people were gathered to watch a football game, Fresno Police Lieutenant Bill Dooley said.
Deputy Chief Michael Reid told the Fresno Bee and local TV stations that a total of 10 people were shot, with three found dead in the backyard. A fourth person died in hospital. Six others are expected to survive and are recovering at the hospital.
All the victims were Asian men ranging from 25 to 35 years old.
Mr Dooley said: "What we do know is that this was a gathering, a family and friend gathering in the backyard. Everyone was watching football this evening when unknown suspects approached the residence, snuck into the backyard and opened fire."
The victims were taken to Community Regional Medical Centre in critical condition, and some are now stable, the TV stations reported.
About 35 people were at the party when the shooting began.
No one is in custody in connection with the shooting. Police said there was no immediate indication that the victims knew the perpetrators.
Police are going door-to-door in search of surveillance video that might help them track down the suspects. The shooting took place about half a mile from the city's airport.
Agents from the US Bureau of Alcohol, Tobacco, Firearms and Explosives field office in San Francisco were responding to the shooting, the Bee reported.
It was at least the second fatal gun attack on Sunday in southeast Fresno, the Bee reported. A man in his 20s was shot to death at a home in another part of the city. Police have not said whether the incidents could be connected.
Sunday's shootings in Fresno also come on the heels of at least two mass shootings in California. On Thursday, a 16-year-old student at a Southern California high school shot and killed two classmates and wounded three other teenagers before shooting himself in the head. He died the next day.
And on Saturday, police in San Diego said a husband shot and killed his wife and three of their sons before killing himself. A fourth son wounded in the shooting was on life support on Sunday, family members said.