Gunman kills one and wounds three others outside a California polling station

Two people were killed and two others were wounded in an Election Day shooting outside a southern California polling place.

The shooting took place shortly after 2 p.m. local time in a residential area in Azusa, reported the Los Angeles Times.

The gunman, who investigators briefly identified as a woman as the situation unfolded, was found dead in a home after barricading himself inside.

A man in his 70s was pronounced dead at the scene, and three other victims were treated at a nearby hospital.

Officers called to the scene "were met with gunfire," authorities said, and were "pinned down" by the shooter, who reportedly fired 20 rounds at the responding deputies.

They were eventually able to remove themselves to a safer distance without any injuries.

Two elementary schools where polls are located were locked down about 2:15 p.m., along with a nearby day care and preschool.

“This is a very volatile and critical situation,” said Officer Jerry Willison of the Azusa Police Department.

“It’s very early to tell what the motive is, but it appears to be concentrated on the residential side, not at the polling station,” said Azusa Police Chief Steve Hunt.

Authorities asked voters to avoid the area and cast ballots at alternate polling locations.

One voter told KTLA-TV that about 30 people were briefly locked down inside a polling station, and up to 20 children were evacuated from a gym at another polling location.

Voters were still allowed to cast ballots while they were locked inside.