A lady shot and injured three individuals at YouTube’s HQ in Northern California before executing herself, police say.

A 36-year-old man left in a critical condition is accepted to be the suspect’s boyfriend. 2 women, 27 and 32, were likewise shot.

Police are yet to recognize the suspect, who was armed with a handgun, and did not state what was the reason for the assault.

YouTube workers depicted scenes of panic as the occurrence unfurled.

Such “active shooter ” occurrences are overwhelmingly done by men – a FBI report found that out of 160 occurrences between 2000-2013 just six of the general population who opened fire were ladies.

The suspect approached an outside porch and dining area near lunchtime and opened fire, NBC revealed.

San Bruno Police Chief Ed Barberini said officers landed at the workplaces 12:48 (19:48 GMT) local time to locate a “chaotic scene” with various individuals escaping.

Images broadcast on local TV stations demonstrated employees leaving with their hands raised. Other film seemed to demonstrate evacuees forming a line before being exclusively searched by police.

One individual with a bullet wound was found at the front of the organization central station, Mr Barberini said. Minutes later police found a lady who seemed to have shot herself, he said.

Two further casualties were later found at an adjacent business.

A worker at an adjacent fast food restaurant revealed to Fox station KTVU he had treated a young lady who endured a bullet wound to the leg.

He said he had molded a temporary tourniquet from a bungee rope as they sat tight for first responders.

A few YouTube workers tweeted about the assault as it was occurring.

Product manager Todd Sherman said individuals fled the building in panic as the shooting unfurled.

Another worker, Vadim Lavrusik, tweeted he was barricaded in a room with other staff. He later said he had been evacuated.

The three injured were taken to Zuckerberg San Francisco General Hospital. Authorities said the 32-year-old lady’s condition was serious and the 27-year-old’s condition was fair.

A fourth individual was additionally taken to hospital with an ankle injury sustained while endeavoring to escape, Mr Barberini said.

Somewhere in the range of 1,700 individuals work at the YouTube HQ. The organization is owned by Google and is the area’s biggest employer.