Photo: VCG

Four persons were killed and other six were wounded in a mass shooting incident at a backyard family gathering Sunday in Fresno of California, 350 km north of Los Angeles, local police confirmed.

Police received shooting report just before 6:00 pm local time (0200 GMT Monday), Bill Dooley from Fresno Police Department told reporters.

The incident occurred when a group of people gathered in a resident's backyard watching football game. An unknown shooter sneaked into the house and opened fire before fleeing, he said.