A white 16-year-old girl is accused of plotting to attack a mostly black church in a north Georgia city, where police say she planned to kill worshippers because of their race.

Bethel African Methodist Episcopal Church has a predominantly black congregation, Gainesville Police Chief Jay Parrish said in a Tuesday statement.

“Our investigation indicated the church was targeted by the juvenile based on the racial demographic of the church members,” he said.

Students, school administrators and law officers worked together to thwart a “potentially horrific incident,” he added.

The plot came to light when Gainesville High School students told administrators the 16-year-old had a notebook with detailed plans to kill worshippers at the church, Parrish said.

The girl is charged with criminal attempt to commit murder, the police chief said. She’s being held in a youth detention center in Gainesville.

Specific details of the alleged plot haven’t been released, but Parrish said it came to light Friday when school administrators contacted police. Police did not release the girl’s name Tuesday.

Gainesville is about 50 miles northeast of Atlanta. It’s a city of just over 40,000 people, about 17% of whom are African-American.