WATCH: YouTube Active Shooter Video Coverage

A woman opened fire Tuesday afternoon at the YouTube headquarters in Northern California and then allegedly took her own life, according to officials. At least three people were injured in the incident. Nasim Aghdam has been identified as the suspect, according to NBC News.

San Bruno Police Chief Ed Barberini said the deceased victim found at the scene may have been Aghdam. She appeared to have killed herself, but the incident is still under investigation.

Aghdam is believed to have known at least one of the victims, two law enforcement officials told CNN. Law enforcement sources also told The Los Angeles Times that the shooting was a domestic incident, with Aghdam targeting someone who worked on the YouTube campus.

According to Barberini, the shooting took place while employees were having lunch on a patio.  The violence began at about 12:45 p.m. in a courtyard outside the company’s headquarters, just south of San Francisco.

“We did encounter one victim with an apparent gunshot wound, towards the front of the business as we arrived. Several minutes later, while conducting a search of the premises, officers located a second individual with a gunshot wound, that [may have been] self inflicted,” Police Chief Barberini said during a press conference.”We are still working on confirming that. Two additional victims were located several minutes later at an adjacent business. The extent of all the injuries of our victims, are unknown right now. They were all transported for emergency medical care… We have four victims who have all been transported for gunshot-related [injuries].”

According to KRON4, the woman drove up from San Diego Tuesday, a source told the station. Police say the shooter used a handgun, reports KRON4.

According to the video below, a spokesman for San Francisco General Hospital says they received three patients after the shooting at YouTube’s headquarters, with the surviving victim’s conditions ranging from fair to critical.

You can watch a livestream of coverage from CBS News below.

Witnesses at the scene described seeing a woman shooting a gun in a courtyard as others ran for their lives, reports CNN.

According to CNN, one witness inside a cafe near the shooting said the gunfire didn’t immediately register with him.

“It was a surprise, because you don’t really expect something like that,” the man told CNN affiliate KPIX. “I heard some pops, I obviously thought it was balloons, but then I thought that doesn’t make sense, not today. Then I heard more shots and that’s when everyone started scrambling for the door.”

Steve Dempsey says he saw wounded victims moments after the shooting in San Bruno. Dempsey describes the scene of the shooting as an injured woman who appeared to be shot in the foot came limping across the street from the YouTube headquarters.

Vadim Lavrusik, a YouTube product employee, tweeted he and others hid during the incident.

“Heard shots and saw people running while at my desk. Now barricaded inside a room with coworkers,” he wrote.

YouTube CEO Sundar Pichai took to Twitter to express his condolences to the victims of the shooting, thanking police and first responders and calling the shooting a “tragedy.”

Dispatch audio of the shooting was also released, showing the chaos and confusion as the shooting unfolded. You can hear the dispatch audio below.

This story is still developing and will be updated as more information is released.