The group seemed to be subject to more scrutiny than predominantly white school groups at the museum

The field trip to Boston's Museum of Fine Arts was supposed to be a reward for good grades and excellent behavior.

Instead, chaperones say, students from the Helen Y. Davis Leadership Academy Charter Public School in Dorchester, Massachusetts, left in tears last week after they were subjected to racial profiling from museum employees and offensive comments from visitors.

On Friday, the museum again apologized to the students and the middle school, where the majority of students are black or Latino. The museum said in a statement Friday that, following an investigation, it had banned visitors accused of making racist comments and is retraining staff and security.

"These young people left the Museum feeling disrespected, harassed and targeted because of the color of their skin," said the museum's director, Matthew Teitelbaum. "And that is unacceptable."

The 26 seventh-graders who went on the school trip are students of color, according to school officials, and the allegations have prompted a larger conversation about how museums and other elite cultural institutions can be uncomfortable spaces for people of color.

Security guards closely shadowed the seventh-graders throughout their visit and followed them from one gallery to another, Marvelyne Lamy, an English language arts teacher at the charter school, told local media outlets. She and her students noticed that their group seemed to be subject to more scrutiny than predominantly white school groups that were touring the museum at the same time.

"We were instructed not to touch any of the artifacts in the museum, yet the white students there touched the displays several times while security looked on without saying anything," Lamy wrote on Monday in a Facebook post, where she first detailed her frustrations with the museum. "The minute one of our students followed suit, the security guards would yell at them that they should not touch exhibits."

A staff member who was explaining the museum's rules allegedly told the group, "No food, no drink, no watermelon." Lamy told the Globe that she did not hear the comment herself, but students who were upset by the apparent reference to a well-known racist trope told her about it. One 13-year-old told the Globe that the remark left her feeling angry, uncomfortable and disrespected.

The middle-schoolers also reported hearing disparaging remarks from other museum visitors. One student told Lamy that she had been dancing to music played as part of an exhibit when a museumgoer said, "It's a shame that she is not learning and instead stripping." Another seventh-grade teacher at the school, Taliana Jeune, described the remark differently, telling WCVB that the student had been warned, "I hope you're paying attention so that you don't become a stripper.'"

The remark about stripping was the last straw, Lamy wrote on Facebook, and told the seventh-graders that they were leaving right away. As they were making their way out of the museum, some students paused by the entrance to an African art exhibit. Lamy said a woman walked by and commented, "Never mind, there's f---ing black kids in the way."

Lamy said she never planned to set foot in the museum again.

"We reported all these incidents to the staff at the MFA, and they just looked on with pity," she wrote on Facebook. "They took our names and filed a report. Their only solution, they will give us tickets to come back and have a 'better' experience. We did not even receive an apology."

To some critics, the middle-schoolers' experience demonstrated why the MFA and other prestigious cultural institutions remain stubbornly white. Racism, wrote Globe opinion columnist Renee Graham, "compels us to self-segregate, to do it to ourselves before it can be done to us. And we tick off the places we won't go - certain ballparks, restaurants, theaters, symphony halls, hospitals and stores. And museums."

The museum has made a concerted effort to attract a more diverse audience in recent years. In 2015, the museum found that nearly 80 percent of people who visited were white, which led to targeted outreach and initiatives aimed at making the museum more inclusive. Two years later, Globe reporters who visited on a Saturday found that, out of roughly 3,000 guests, only about 4 percent were black.

On Wednesday, nearly a week after the field trip, top museum officials apologized in an open letter that acknowledged that the students had "encountered a range of challenging and unacceptable experiences that made them feel unwelcome."

On Friday, the museum revealed the conclusions of its investigation, which included re-creating the students' three-hour visit from security footage and speaking to dozens of people.

It said it could not "definitively confirm or deny" that students were told "no food, no drink, no watermelon," saying a staff member recalled saying "no food, no drink and no water bottles" were allowed. Though the museum typically allows guests to carry closed water bottles, school groups are advised that no drinks are allowed in the galleries.

The museum also said security guards' rotations may have unintentionally appeared to the students as if they were being followed, but added, "It is unacceptable that they felt racially profiled, targeted and harassed."

Lastly, the museum said its investigation found that other visitors made racist comments to the students, which led to the revocation of their membership and their banning from the museum.

The museum vowed to "adapt security procedures . . . to make sure all people feel welcome," provide additional training to employees that work with visitors and continue mandatory unconscious bias training for all staff members.

Teitelbaum has asked to meet with students at the school next week.

"This is a fundamental problem that we will address as an institution, both with immediate steps and long-term commitments," Teitelbaum said in the statement. "I am deeply saddened that we've taken something away from these students that they will never get back."

The experience ended up teaching the seventh-graders "an unfortunate lesson," Arturo Forrest, Davis Leadership Academy's principal, told the Globe.

"This was a strong group of students that went, they excelled academically," he said. "The shock of it for them was, 'We are the top and we carry ourselves the right way as leaders.' You know, it was very eye-opening for them.

Lamy agreed.

"I had to tell them, you know, as a black or brown person, you have to work 10 times harder," she told reporters on Thursday. "Unfortunately, that's the world that we live in."