(CNN) — A gunman on Wednesday killed three people at a UPS facility in San Francisco before killing himself, Assistant Police Chief Toney Chaplin told reporters.
Two other people were shot and survived, he said. The gunman fatally shot himself when confronted by police, authorities said.
Police have not released the names of the gunman or the victims.
Officers responded to a report of an active shooter about 8:55 a.m. local time (11:55 a.m. ET) at the UPS San Francisco Customer Center, a couple of blocks east of Franklin Square. The package sorting and delivery facility employs 350 people.
Officers arrived to learn the suspect was still inside the building, Chaplin said. A police “contact team” soon found him armed with an assault pistol, the assistant chief said.
“The suspect put the gun to his head and immediately discharged the weapon,” he said. No officer fired a shot during the confrontation, according to Chaplin.
UPS spokesman Steve Gaut released a statement saying that six employees were involved in a “shooting incident” but that the company cannot provide any identifications until the police investigation is complete.
Chaplin said that although the suspect was wearing a UPS uniform, investigators have yet to confirm whether he was an employee.
Chaplin said authorities don’t know at his point whether the shooter targeted victims. Earlier, Chaplin said there is no indication the shooting was terror-related, without providing a motive. Five other people were injured, likely during the evacuation, he said.
Police have completed the search for additional victims. Authorities have interviewed all witnesses and are talking to the victims’ families, he said.
A woman named Michelle, who did not want to provide her last name, was walking to work across the street from a UPS facility when she saw several UPS employees running down the street. They told her to run because there had been a shooting, she told CNN, explaining she ran about a block with the workers.
“I was confused. They crossed the street and when they got to me, they said, ‘Run, there is a shooter,’ so I started to run with them,” she said. “Several of them said it was a driver they worked with who had a gun and opened fire. I feel terrible for the people hurt and for the UPS team that was there but survived.”
Antonio Salic told CNN he was working in a house across from the UPS building when he heard shots fired.
“I peeked out the window,” he said. “I saw people getting out (of the building), and they were wounded. A lot of people were running.”
The construction worker said he also saw people on the roof with their hands up, letting police know they were unarmed.
“Police approached and they were taken to a safe place,” he said.
In its statement, UPS said the company wasn’t immediately sure of the status of the survivors who were taken to the hospital.
“The company is saddened and deeply concerned about affected employees, family members and the community we share,” the statement said.
Aerial footage showed police leading dozens of people, many in matching brown work uniforms, out of a building. A tactical vehicle arrived shortly thereafter.
The site of the shooting was in the Potrero Hill area, a largely residential neighborhood. The shooting was also not far from a Whole Foods market and the brewery that makes Anchor Steam beer.
Residents were warned to avoid the area because of heavy law enforcement activity.