The Fremont, Neb., school district has banned its students from wearing necklaces that look like rosaries after police told school officials such necklaces were also being worn by gang members.
Fremont Superintendent Steve Sexton told Omaha television station KETV the policy is to protect students.
He said police told school leaders the necklace is being used as a symbol of gang affiliation.
Some parents are upset by the ban, saying they feel feel their children are not being allowed to express their religious beliefs.
Sixth-grader Elizabeth Carey said the school adopted a policy last year banning the necklaces.
"The principal said I couldn't wear my necklace at all because gangsters were wearing it," she said.
She said the necklace is part of an outfit that she hopes expresses her faith.
"I'm wearing a cross necklace, a cross T-shirt, and a cross bracelet," she said. "I'm thinking of how Jesus died on the cross and how he gave up all his sins for us."
Carey said she will continue to make a statement with her wardrobe through cross necklaces and shirts.
"I'm deciding to stand up for Jesus and do whatever I can to stop this," she said.
Omaha Catholic Archdiocese Chancellor Rev. Joseph Taphorn said Christians shouldn't have to give up a symbol of their faith because others misuse it.
The American Civil Liberties Union opposes the policy, saying it violates the rights of free speech and religion.