A 17-year-old girl was killed and five other people were wounded in a shooting at a party, police said.
Officers responding around 3.30am local time to reports of gunfire found six people shot at an apartment building in Chico, Northern California, police Chief Billy Aldridge said.
All the victims were taken to hospitals, and the teenager died at a hospital, he said.
This comes as there were multiple deaths in another mass shooting in Texas.
Two men, ages 21 and 19, and a 17-year-old girl remained hospitalised in stable condition with non-life-threatening injuries in California, the chief said.
Two other men, ages 18 and 20, were treated at the hospital and released, Aldridge said.
The shooting appeared to be an isolated incident, and there was no ongoing threat to the community, police said.
They released no information on the shooter.
Police had been called to the same address about 30 minutes before the shooting and arrested a man on suspicion of brandishing a firearm, Aldridge said.
That suspect matched the description of a man who was asked to leave a separate party about a mile away around 12.30am, Aldridge said.
A fight broke out at the earlier party, and two people were hospitalised after being struck in the head, one with a bottle and one with a firearm, the chief said.
Several streets were closed Saturday as investigators combed the area for evidence.
At least three parked cars had bullet holes and shattered windows, according to the Chico Enterprise-Record.
Both parties were in neighbourhoods near California State University in Chico, a city with about 101,000 residents 90 miles (145 km) north of Sacramento.
Lt. Brian Miller called the area a "hot spot" for police service calls.
