Members of a parents group at a Bucks County high school say the swastikas and slurs found scrawled in student bathrooms last week were not the first racially charged incidents at the school, and they want the district to implement a long-term diversity plan.

"Parents are really, really concerned," Bernell Holmes, a member of the group Concerned Parents of Council Rock School District, said Monday.

Earlier, school administrators gathered students at Council Rock North High School for an assembly and small-group discussions about the swastikas, an antigay slur, and messages, including "I love Trump," found in bathrooms. A Latina student also found a note in her backpack telling her to return to Mexico, Superintendent Robert J. Fraser said in a letter to parents.

The acts are the focus of an ongoing criminal investigation, Bucks County District Attorney Matt D. Weintraub said Monday while declining to elaborate.

They also follow a string of racially and ethnically charged incidents that have come to light nationwide since Donald Trump's election as president.

Council Rock is a high-achieving school district, and Council Rock North has a student body that's 87 percent white, 1.3 percent black, and 2.4 percent Hispanic, according to state data.

"What is NOT right is for any student at Council Rock North to feel unsafe or to be harassed because of who they are or what they think," principal Susan McCarthy said in an announcement to students that was also emailed to parents.

Neither the superintendent nor the principal responded Monday to requests for comment.

At assemblies, students heard from administrators and then met in small groups, said junior Jayla Johnson.

She wondered why the administration waited until Monday to address the issue and was skeptical the school would be able to catch and punish the perpetrators, Johnson said.

"Some people were saying that they were afraid and scared to come to school because they were afraid they were being targeted," said Johnson, 16.

The African American student said she has had racial slurs used against her by classmates and once complained to administrators after a student wore a Confederate flag to school. She said she knows others who have been called racial or sexual slurs as well.

The superintendent planned to be available to meet parents on Monday and Tuesday from 7 to 9 p.m. at the Chancellor Center in Newtown.

The school will also hold a follow-up meeting with students facilitated by the Peace Center at a later date and is looking into other activities such as peer training and a "cultural week," the principal said in the announcement. "Some will be short-term responses, while others will be long-term ones that will hopefully become an important part of our school culture," she said.

Johnson's mother, Robyn, said the Concerned Parents group, which meets twice a month with about 140 parents, has previously asked the school to implement sensitivity training, examine the curriculum, and hire more diversely.

The steps the school is now taking are good to start, she said, but she wants a long-term plan.

"When the children . . . come up against this, there's no one to advocate for them," she said. "They don't trust anyone in the school."