Two killed by gunfire near US poll place

One man has been killed and two women were wounded when a gunman opened fire with an assault rifle at a house across the street from a polling station in the southern California town of Azusa, before the gunman was also found dead.

The midday outburst of gun violence in the normally quiet foothill community 40 km northeast of Los Angeles disrupted voting at two polling places and prompted security lockdowns of a park and two public schools.

Los Angeles County Sheriff's Lieutenant John Corina said the bloodshed had "nothing to do with" Election Day. "It just happened to be across the street," he said.

Corina said the two wounded women were struck by stray bullets. The Los Angeles Times, citing a law enforcement source, said one of the victims hit by gunfire was on the way to a polling place to vote.

Azusa police earlier described the shooter as a heavily armed female and said there were reports of a possible second, male suspect.

However, Corina later said police had confirmed that only one suspect had been involved - a man found dead inside the house by police. He said it was not immediately clear whether the gunman was killed by police or had taken his own life.

Officers responding to initial reports of gunshots came under fire themselves as they tried to assist victims found bleeding outside the home, according to accounts from Azusa police and the sheriff's department.

Police returned fire and then surrounded the house, cornering the suspect inside, authorities said.

Authorities said the motives of gunman were unknown.