Eight people were shot during a dice game at an apartment complex in San Bernardino, late Sunday, police said.
A 17-year-old boy is in grave condition, while another victim is in extremely critical condition, said San Bernardino Police Capt. Richard Lawhead. The remaining six victims suffered non-life-threatening injuries.
Police initially said 10 people had been shot, all of them apparently adults, but Lawhead revised the tally early Monday to eight, including at least one minor.
Though there is a lot of gang activity in the area, Lawhead could not say for certain if that was a factor in the shooting but also wouldn't rule it out.
The shooting took place in a common area of the complex, he said.
There is no suspect in custody, he said.
Officers got a call reporting shots fired at the complex, located on the east side of the city, Sunday at 10:45 p.m.
"We believe that there was an exchange of gunfire," he told reporters at the scene.
Handguns and rifles appear to have been involved in the shooting, Lawhead said, but no weapons have been recovered. Determining specifically what led to the violence has been difficult because victims and witnesses refuse to cooperate with police, he said.
San Bernardino police requested help from neighboring agencies to control a "hostile crowd" that emerged from the apartment complex in the wake of the gunfire, according to a written statement issued by the agency.
A passing car and a nearby apartment were also struck by bullets, police said.
"I can tell you multiple shots were fired, I don't want to guess how many," Lawhead said. "We do have some people that have been transported to the station for investigative purposes so we hope that they will yield information for us."
Neighbors describe hearing multiple gunshots
Alysa Marie, who lives near the apartment complex, told CNN she heard 15 to 20 gunshots fired in rapid succession.
"My brother-in-law could hear bullets flying past our house. He was outside at the time of the shooting," Marie said.
"About five minutes later, the helicopter was circling around our street, talking on the loudspeaker saying to put down the weapons, for the people who were on the ground to get up and get to safety and to let the law enforcement do their job."
Marie said there was a large police presence and she heard about 10 ambulances drive past.
Another neighbor who asked that his name not be used also described hearing multiple shots from his house a block away.
"I heard around four shots, then what sounded like a motorcycle speeding off. After that, just a continuation of gun shots," he told CNN.
Neighbor Christine Loy said her thoughts were with the victims, especially the severely injured teen.
"That baby is fighting for his life right now and all my prayers are with him and his family," she said.
Officials told KTLA that while the apartment building was fitted with cameras, none of them were working at the time of the shooting.
Investigators need cooperation from witnesses to solve the case, Lawhead said. Fear of retaliation may be keeping some form coming forward.
"I think some of it is fear," he said. "There are really good people who live here because this is where they can afford to live. And they're held captive by some of the violent, illegal activity that occurs here. But unless we know it's occurring and know who the people are involved in that, we can't stop it."
KTLA's Brian Day contributed to this report