Police shot and killed a woman on a California elementary school playground after she came to the campus with a large knife, Modesto police told The Modesto Bee.

The newspaper reports that minutes before the shooting, the woman was seen near Catherine Everett Elementary School hitting herself repeatedly in the head with the knife.

Police say children saw the woman on the playground, and school officials immediately ushered them back into classrooms.

When police arrived on the scene, the woman allegedly charged at them with the knife. At least one of the officers shot at the woman, fatally wounding her, according to The Modesto Bee.

The school was locked down while police investigated, but children later were released to their parents and guardians.

The victim's identity wasn't immediately known, and no students or school staff were harmed in the incident, according to The Modesto Bee.