A gunman has killed five people, including his wife, in California.

Officials in Bakersfield, which lies about 90 miles north of Los Angeles, said the attacker then turned the gun on himself.

The gunman and his wife had shown up at a trucking business in the town on Wednesday evening, where he confronted another man.

Kern County Sheriff Donny Youngblood said: "The suspect, the husband, shot the person at the trucking company and then turned and shot his wife."

Kern County Sheriff Donny Youngblood speaks to the media, 12-09-2018. Image:  Sam Morgen/AP/Press Association Images

The gunman then chased another man from the business and killed him in front of a nearby sports store.

Another two people were shot at a home nearby.

The gunman then carjacked a woman who was with her child, but they both managed to escape unharmed.

As he drove down a highway, the gunman was spotted by a sheriff's deputy and pulled over.

When he was confronted at gunpoint, he shot himself in the chest.

Mr Youngblood said the entire incident took place over 10 to 15 minutes, adding: "This is the new normal, if you look across the country. Six people lost their lives in a very short period of time."

It is not known how the victims are related, and the gunman's identity is yet to be made public.

Detectives are working on the basis that the shootings were not at random.

The shootings were witnessed by about 30 people, who are now being interviewed by the police.