(CNN) - UPDATE:
Preliminary numbers indicate "upwards of 14 people" are dead and "upwards of 14 people are injured" after a shooting Wednesday in San Bernardino, California, Police Chief Jarrod Burguan told reporters. The numbers could change, he said.
As authorities search for three suspects, courts and government buildings in the area have been "shut down and locked down."
The suspects were armed with long guns, Police Chief Jarrod Burguan told reporters. "These were people that came prepared. ... They were armed with long guns, not hand guns," he told reporters.
Authorities do not know whether the shooting was a terrorist incident, said David Bowdich, assistant director for the FBI's Los Angeles field office. "At this point, I know one of your questions is going to be 'Is this a terrorist incident?' I will tell you right now, we do not know if this is a terrorist incident," Bowdich told reporters.
Burguan adds, most of the victims were "centrally located in one area of the facility." Authorities haven't confirmed what was going on at the facility when the shooting occurred, he said. "I've heard everything that it was a meeting to a potential, like a lunch type gathering, maybe for the holidays," he said.
The shooting occurred at the Inland Regional Center, a facility for people with developmental disabilities. It is unclear how many people were at the facility at the time of the shooting. The center's Facebook page says it employs nearly 670 staff members at its facilities in San Bernardino and Riverside counties, providing service to more than 30,200 people.
CNN affiliate KABC, covering Wednesday's shooting in San Bernardino, California, showed video of a group of people walking out of a facility with their hands in the air.
A man named Marcos Aguilar told CNN affiliate KABC that his wife had just gotten out of a building where a shooting occurred in San Bernardino, California. "She said the guy came in next to her office and I guess started shooting. Then he locked himself in in her office. They've seen bodies on the floor. She said right now ambulances are taking people out in stretchers," he said.
Loma Linda University Medical Center is expecting an unknown number of patients from the San Bernardino, California, shooting, spokeswoman Briana Pastorino said. She said the extent of the anticipated patients' injuries is not clear.
Police in San Bernardino, California, tweeted a warning Wednesday that there was an active shooter situation.
The San Bernardino County Sheriff's Department tweeted that there was an "active shooter in the area of Orange Show Rd/Waterman Ave near Park center."
It urged people to avoid the area.
The San Bernardino Fire Department said on Twitter it was responding to reports of a "20 victim shooting incident."
San Bernardino is a city of just over 200,000 people located 60 miles east of Los Angeles.