MONTPELIER, Vt. —The Burlington School District says it’s working on a plan to improve race relations among staff after the diversity office director and two other black employees complained of discrimination.

But a lawyer for the employees says the district has been slow to act.

Nikki Fuller, director of the District’s Diversity, Equity and Community Partnership Office; Henri Sparks, the office’s equity director; and DaVerne Bell, the director of diversity education engagement, filed a complaint in June 2015 to a school board committee that they were experiencing a lack of respect from colleagues and outright harassment and discrimination. Bell has since left the office.

“A clear message has been sent across the district that teachers are not to listen to or to engage with the diversity and equity office. They are not to do anything additional involving diversity and equity,” the complaint said of the district that has become increasingly diverse in the largely white state primarily due to African and other refugees resettling in the area.

According to the district’s 2014-2015 annual report, 65.2 percent of students were white, 14.3 percent were black and 11.5 percent were Asian.

After the complaint, the school board hired an outside investigator who concluded that “pervasive racism” exists but no specific instances of racially motivated conduct or retaliation were found.

“The lack of procedure relative to racism and discrimination complaints leaves the (diversity office) feeling that the work done by them will only go as far as a certain point, and then the issue is dropped,” the investigator’s report said, while noting that relations seemed to be improving since Yaw Obeng became superintendent last year.

Last month, the school board voted to direct the superintendent to develop and implement an improvement plan over the next year, as first reported by Seven Days weekly newspaper.

Robert Appel, a lawyer for the employees who filed the complaint, said the district has not addressed the concerns quickly enough. Noting that the board resolution was passed Aug. 2, he said, “So you know time marches on. You know they made findings that they have problems and it just continues to slide.”

Obeng said the district wants to put a plan in place that gives staff a safe place to go to report discrimination.

“One of the things I was pleased about was for the board to actually be open enough to recognize that there is a level of systemic discrimination … and that we should be taking action,” he said.

The board said it did not unanimously support some of the specifics of the investigation but it was prepared to work with the findings of “pervasive racism” and address it.