A shooting at YouTube headquarters in San Bruno, California Tuesday left several people hospitalized, according to reports. The shooter is believed to have died from a self-inflicted wound, San Bruno Police Chief Ed Barberini said during a press conference.

Barberini confirmed that three people were wounded — which included two females, who were classified as fair and serious, and one male, who was critical. One person was found dead, and Barberini said that may have been via a self-inflicted gunshot wound.

Barberini confirmed the suspect is female.

A local news report that was broadcast on Fox News quoted a spokesperson from San Francisco General Hospital as saying it is "receiving multiple patients" related to the shooting. The San Bruno​ city manager told a local news station that Stanford University Medical Center was expected to receive four or five patients.

A witness interviewed on the same broadcast said she heard multiple shots in at least two bursts.

President Donald Trump tweeted that his "thoughts and prayers are with everybody."

Was just briefed on the shooting at YouTube’s HQ in San Bruno, California. Our thoughts and prayers are with everybody involved. Thank you to our phenomenal Law Enforcement Officers and First Responders that are currently on the scene. — Donald J. Trump (@realDonaldTrump) April 3, 2018

Live video from helicopters showed police frisking people leaving the scene.

Police and federal agents, a group that included the ATF, descended on the sprawling campus after receiving dozens of calls about shots fired. Officers in SWAT gear could be seen walking toward the building behind shields, with guns at the ready.

One witness interviewed by KTVU said he saw several people get shot, including one person who was hit by multiple rounds. He said the shooting occurred in the courtyard at the YouTube headquarters during some sort of lunch gathering.

YouTube employee Vadim Lavrusik tweeted that there was an "active shooter" at headquarters, and that he was barricaded inside a room with coworkers. He later tweeted that he was evacuated and got outside..

Active shooter at YouTube HQ. Heard shots and saw people running while at my desk. Now barricaded inside a room with coworkers. — Vadim Lavrusik (@Lavrusik) April 3, 2018

Safe. Got evacuated it. Outside now. — Vadim Lavrusik (@Lavrusik) April 3, 2018

The White House said President Donald Trump had been briefed and that his administration was monitoring the ongoing situation in San Bruno.

Some employees recounted frantic scenes as they fled, with one saying he saw blood on the floor as he escaped.

"We were sitting in a meeting and then we heard people running because it was rumbling the floor. First thought was earthquake," employee Todd Sherman tweeted.

"I looked down and saw blood drips on the floor and stairs. Peeked around for threats and then we headed downstairs and out the front."

The police department said in an official tweet, "We are responding to an active shooter. Please stay away from Cherry Ave & Bay Hill Drive."

One image posted by a Twitter user showed employees being led out of the building with their hands up, with no further explanation.

Witnesses reported helicopters on the scene as well as police SWAT teams.

Google communications tweeted: "Re: YouTube situation, we are coordinating with authorities and will provide official information here from Google and YouTube as it becomes available."

YouTube headquarters is located some 30 miles from the main Google campus in Mountain View

Stanford hospital said "4-5 patients en route to hospital – unknown injuries and conditions," CNN reported.

The San Bernardino Police Department tweeted at 4 p.m. EDT that there was police activity at the site, and told people to "please stay out of the area."

Police activity at 901 Cherry Ave, please stay out of the area. pic.twitter.com/H6iAj0g7ra — San Bruno Police (@SanBrunoPolice) April 3, 2018

AFP contributed to this report.