The Osseo Area Schools board chairman abruptly resigned Friday after mounting pressure from parents and teachers who called for him to step down amid allegations that he posted anti-Muslim and racist comments on social media.

Robert Gerhart, who had been on the board since 2015, said he’s not racist, xenophobic or Islamophobic. But, he said, the allegations have hindered his ability to be an effective school board leader.

“This had a negatively huge impact on my family and the organization,” Gerhart said in a phone interview. “I don’t care about my position more than I care about the organization.”

His resignation is effective immediately

The board chairman drew criticism last week after he proposed school staff be allowed to carry firearms to help protect students.

Soon afterward, racist and Islamophobic social media posts allegedly authored by Gerhart started surfacing on Facebook. Gerhart quickly removed the social media account where the pictures and comments originated, but not before critics began sharing them publicly. In an interview, he said some of the posts were his, but others were either misunderstood or fabricated by critics.

The district had been flooded with e-mails and calls demanding his removal. Parents and teachers had planned to rally at the school board meeting on Tuesday, urging Gerhart be dismissed.

“It’s important for school board members to play a leadership role in modeling the core values of our organization, and I respect Mr. Gerhart’s consideration of the negative impact of his actions,” Osseo Area Schools Superintendent Kate Maguire said Friday in a written statement.

Maguire said she has fielded numerous e-mails and calls from faculty members and parents in recent days.

“Parents have been upset and angry. Staff have been distressed,” Maguire said. “There is no place for Islamophobic and racist comments in our district.”

Comments written by Gerhart and posted on a Google Plus page include one saying “Umm, yeah. I’m just going to put this one out there and leave it at that.” His comments were connected to a picture of a building on fire with the headline “Migrants Burn Down Hall: ‘There’s Not Enough Nutella and Gummibears!’ ”

Gerhart said his intention was misunderstood when he posted the image. He said he shared the picture because he found it strange. “Why would you burn a place down because there are not enough Nutella and Gummi Bears?” Gerhart asked.

Meanwhile, another post that drew sharp criticism included a picture of a man eating uncooked meat with the headline: “Minnesota Muslim Eating Bloody Meat Introduces Horrified Citizens To His Latest ‘Game’ ”

Gerhart denied reposting that picture on his account. “It’s not me,” he said.

“There are stupid things that I have posted in the past, and I will own up to them,” he said. “But this is not mine.”

There are five other members on the school board and three seats, including Gerhart’s, are up for re-election in November. He was elected chairman last year.

“I sincerely apologize for any hurt, pain, confusion, embarrassment, or anger the statements on Mr. Gerhart’s social media accounts may have caused,” school board director Jessica Craig said. “I am saddened by what I have read and it does not reflect my own personal thoughts or opinions.”

Gerhart said he faced intense opposition to his gun proposal, and said in hindsight he would have taken a different approach in rolling it out.

“I expected there would be blowback and commentary,” he said. “I didn’t expect what’s been happening since. I would have brought it up probably more directly to fellow board members instead of bringing it up publicly. If anything, I expected the response to be passionate but reasonable, and what I’m seeing is more passion than anything else.”

Osseo Area Schools, the fifth largest school district in the state, serves 21,000 students and has the third largest number of students of color in Minnesota. About 57 percent of its students are kids of color and hail from eight different cities — Brooklyn Center, Brooklyn Park, Corcoran, Dayton, Maple Grove, Osseo, Plymouth, and Rogers.

The American Civil Liberties Union of Minnesota defended Gerhart’s right to free speech, but said those rights can be limited when his speech interferes with the district’s ability to carry out its mission.

“Elected officials still need to be held accountable to their constituents,” Teresa Nelson, the chapter’s legal director said. “And his constituents have first amendment rights to express their disapproval with his messages.”

Sabra Love, whose teenage son attends the Osseo High School, said she was disheartened to read the alleged comments on Gerhart’s page.

“He shouldn’t be in any position where he’s making important decisions about our children’s future,” Love said.