Bakersfield:  A gunman killed five people, including his wife, before turning the gun on himself as a Kern County sheriff's deputy closed in Wednesday, authorities said.

There was no immediate word on what sparked the shootings that took place at a home and a business in Bakersfield, which is 90 miles (145 kilometres) north of Los Angeles.

"Obviously, these are not random shootings," Kern County Sheriff Donny Youngblood told KERO-TV. Six people died in a short amount of time, he added.

The man first showed up at a trucking business with his wife shortly before 5:30 pm where he confronted another man.

"The suspect, the husband, shot the person at the trucking company and then turned and shot his wife, then chased and shot another man who showed up," Youngblood said.

The gunman then went to a home where he shot two people, the sheriff said.

He then carjacked a woman who was driving her child. The woman and child escaped and the man drove to a highway where a sheriff's deputy saw him, Youngblood said.

The gunman saw the deputy and pulled into a lot. When the deputy confronted him at gunpoint the man shot himself in the chest, the sheriff said.

His identity was not immediately released.

Except for the gunman's wife, there was no immediate word on how the victims might have been related.

About 30 people saw the shootings and were being interviewed by deputies, Youngblood said.