After students piled into their middle school bus for the ride home Tuesday, a noisy chorus began: “One, two, three, four, how many n------ are in my store?”

The use of a racial epithet shocked a 13-year-old African American girl sitting among her classmates, and she grew upset as it was repeated with apparent glee. She recorded the moment on her cellphone and showed her parents a seven-second clip when she got to her Rockville, Md., home.

The family posted the video on YouTube, Facebook and Twitter, decrying what they said was the first time their daughter had encountered racism and expressing dismay that it had happened in the prosperous Washington suburb in Montgomery County.

“Our daughter had to experience racism today on her school bus,” her father, Brandon Long, wrote of the bus ride from Robert Frost Middle School. “I am outraged, and I refuse to let this slide.”

In less than 24 hours, the video clip on his Facebook page showed more than 200,000 views.

The family said in a YouTube post — later removed — that the incident was their daughter’s first brush with racism and that they had moved to the area because of its good schools.

“Now we are being forced to choose (quality education or torment),” the post said. “These children on this bus have learned this behavior from home. . . . Within their homes lie our judges, lawyers, doctors, and police officers.”

The phrase students were chanting appears in a popular video clip about racial profiling posted to Vine in 2013, in which four black teenagers are seen in a convenience store under surveillance from a clerk. It has been played more than 10 million times and been remixed and recirculated over the past three years using the hashtag “#Iknowyourstealing”, including in tweets and in a recent YouTube video that has been seen more than 500,000 times.

Montgomery school officials said Wednesday that the group of students who started the chant on the bus was diverse — including a black, Hispanic and Asian student — and might not have meant it as a racial slur, harassment or a put-down. In a recording of the incident, many students appear to be chanting the words.

“The video has a statement,” said schools spokesman Derek Turner. “And they may have been trying to express something expressed in that video.” He added that “there could be, and there might be, some context to this that is not about intimidation.”

School officials said that Joey Jones, Frost’s principal, met with the family involved and was investigating the incident. Jones will work with the district’s equity unit to turn the incident into a learning experience for students and the community, officials said.

“This is a teachable moment to learn about race, diversity and culture in our schools,” Turner said.

School officials said they did not believe that the chant was made against a particular student and added that all students identified as participating will face disciplinary consequences.

In a letter home to parents Wednesday, Jones wrote that the bus driver stopped the bus and addressed the students involved in the chant.

The principal said the behavior was “both offensive and inappropriate” and did not reflect the school’s values.

“As an African American educator, this incident is personally very disturbing, and we must address this incident and issues of race so we all can move forward, together,” Jones wrote.

The girl’s father said in an interview Wednesday that he was surprised to see how jovial and upbeat the students in the video seemed. He said his daughter recounted how the students continued the chant even after the bus driver first tried to get them to stop.

“It shows a lack of empathy to other people’s feelings,” Long said. “It was a poor choice. They did it again knowing this time that they were reprimanded for doing something wrong and that they were being recorded. To me, if you were reprimanded and you knew you were wrong, to do it again shows a lack of care about consequences.”

He said his daughter, who is new to the school this year, came home upset. He said he was shocked. “I’ve never experienced this in my whole life, so having this happen to my 13-year-old daughter is very hard,” he said.

Long said his daughter is aware of the nation’s racial tensions that have been at the forefront the past two years and has heard her parents discuss issues of race.

“She knew that it wasn’t right,” he said. “We teach that if you allow people to get away with it, they’ll continue to do it.”

He said he hopes that other students will learn from the incident, saying it is important not to shy away from conversations about race.

“Her classmates are going to grow up to be influential professionals — police officers, attorneys, judges, politicians — and if they grow up without a strong moral compass, they’re going to continue the same illegitimate practices we see today.”

Jennifer Jenkins contributed to this report.