A Michigan school district canceled its plan for an elementary classroom mini-lesson on gender identity and pronouns after receiving backlash from community members, Dewitt Public Schools Superintendent Shanna Spickard said Friday.

The lesson was announced by the district as a voluntary activity for one first grade class outside of the school curriculum to “promote greater understanding, compassion, and kindness regarding gender identity and the use of pronouns.” The district said it informed parents and guardians in advance of offering the lesson to allow the opportunity for families to opt out of having their children participate.

School district staff members reportedly received “inappropriate, angry, and threatening phone calls, emails, and social media messages” after the announcement, and several staff members had their personal information posted online “to harass and intimidate them,” Spickard said.

“While the vast majority of these inappropriate communications have originated outside of our community, several staff members have expressed feeling anxious, stressed, and even afraid to go to school,” she said. “This is unacceptable.”

Spickard said the district is in contact with local law enforcement, and there is an increased police and administrative presence on grounds as precautionary measures.

“The goal of the voluntary mini-lesson was to help promote Dewitt Public Schools’ vision of a safe, nurturing, and supportive learning environment where all learners can succeed,” Spickard said. “Unfortunately, it has become a major disruption and distraction to that vision in which our staff, administrators, and students feel unsafe.”

On Wednesday, two days before the cancellation, the district remindedcommunity members that the gender identity and pronoun lesson is voluntary and would only be offered for one first grade classroom.

“The mini-lesson is not designed to challenge, persuade, or alter family beliefs. Instead, it aims to promote a safe and respectful learning environment where all our students feel valued,” the district stated.

Community members had mixed reactions to the announcement.

“They don’t need to learn about anything that’s personal or sexualized or gender-specific at 5 years old,” DeWitt parent Brandi Strahan told NBC affiliate WILX, which covers the Lansing, Michigan, area.

A former DeWitt parent also told WILX: “Even if people don’t understand it, it’s all about inclusion and making every kid feel safe and welcome in any district.”

Spickard said the decision to cancel plans for the mini-lesson was not made lightly, and that the development would “please some and disappoint others in the school community.”