San Francisco police officers Thursday morning shot and killed a man who they said was armed with two handguns in the international terminal at San Francisco International Airport.
Sources told NBC Bay Area the man was armed with replicable handguns.
The California Department of Justice will independently review the shooting, Attorney General Rob Bonta announced Thursday evening.
At about 7:30 a.m., SFPD officers responded to reports of an armed individual in the terminal in front of the BART station and confronted the male suspect, who continued to pose a threat despite de-escalation efforts, police said.
Officers then used non-lethal means to try to contain the situation, but the suspect continued to advance, and officers fired shots, killing him, police said. It was not immediately clear how many officers were involved in the shooting.
An Air Canada employee said he stepped off a BART train at about 7:30 a.m. and heard shouting.
"Other patrons started coming off. That's when I start telling everyone, 'Go back! Go back! They don't want us to come back. Shooter! Shooter!'" the airline employee said.
The suspect was not immediately identified.
Police are trying to figure out why he was armed at the airport.
"At this point in the investigation, there's no indication of this incident being involved with terrorism," SFPD Officer Grace Gatpandan said.
One bystander suffered minor injuries in the incident and was treated at the scene before being taken to a hospital, police said.
SFPD will hold a public town hall with additional information within 10 days of the incident, police said.
BART service to SFO was temporarily suspended during the incident, and passengers were routed around the affected area. Service has since resumed, police said.
Flight operations were not affected.
Bay City News and The Associated Press contributed to this report.