A white student on a middle school trip to Washington, DC, spat on a black patron at the Smithsonian's National Museum of African American History and Culture on Friday, prompting his class to be ejected from the museum.

The unnamed male student at Shelton Intermediate School in Connecticut spat off a balcony and hit the person below, according to principal Dina Marks, who was accompanying the students.

"It was an act of stupidity, disinterest, & immaturity, completely inappropriate, " she tweeted Saturday, "but I believe, not racially motivated against that person."

On Friday night, Marks wrote only that the students had returned to their hotel rooms after "an unfortunate incident."

"Our kids are not bad people," she wrote. "We are all pretty sad tonight."

Marks did not immediately respond to a request for comment.

Chris Clouet, the superintendent of Shelton Public Schools, announced the incident via Facebook on Friday night, telling parents the class had been "thrown out" of the museum.

"This is now, regrettably, a pattern of behavior that is disrespectful and does not serve anyone well — including the student who acted inappropriately and embarrassed himself and his school," Clouet said.

Clouet, he urged parents to speak to their children "in an age-appropriate manner about our expectation of how we treat people: Black or White, elder or young, or anyone, a child (or adult!) may perceive as being different."

In a telephone interview with BuzzFeed News, Clouet said the student had been sent home to Connecticut as the other 13- and 14-year-olds continued their trip.

"There will be school-based disciplinary action," he said, declining to provide specific information due to privacy laws.

"But more than the issue of discipline is the issue of teaching and getting past this sort of episode," he said. "I think my job as an educator is to make sure we're educating our children to live in a multicultural world."

About 35% of students in the Shelton Public Schools district are children of color, he said.

Clouet was not sure if the incident was motivated by racism or horseplay, but added that "too often incidents are covered over by claiming it's only a joke."

Pictures the principal shared on Twitter showed the group of roughly 100 students had earlier visited the White House, Arlington National Cemetery, and the Holocaust Museum.

Staff at the African American History museum did not respond to a request for comment.

In May 2017, visitors at the museum were removed from one section after someone left a noose on the floor of one of the exhibit rooms.