A gunman has killed six people in drive-by shootings in the Californian city of Santa Barbara, U.S. police said, according to BBC News.

The shootings took place on Friday, May 23 night near the University of California-Santa Barbara, where two-thirds of the residents are students.

The suspected gunman was found dead in his car with a bullet wound in the head. It is not clear whether the wound was self-inflicted, police said.

Seven other people are in hospital, and being treated for bullet wounds.

The shootings occurred at several sites in the Isla Vista neighborhood, and there were nine crime scenes, police said.

"We have obtained and are currently analysing videotaped evidence that suggests that this atrocity was a premeditated mass murder," Santa Barbara County Sheriff Bill Brown told reporters.

He said police were familiar with a YouTube video entitled Elliot Rodger's Retribution, which shows a young man complaining about years of rejection by women.