A “hyper-complaint dynamic” within the city’s education department explains why so few of the harassment claims made against the agency are substantiated, Mayor Bill de Blasio said Wednesday.

“It’s pretty well known inside the education world of some people bringing complaints of one type or another for reasons that may not have to do with the specific issue — and this is not just about sexual harassment,” de Blasio said at a press conference.

“We have to investigate everything but it is a known fact that unfortunately there has been a bit of a hyper-complaint dynamic sometimes for the wrong reasons.”

The mayor’s comments come less than a week after the city released statistics that show nearly 500 education department employees filed sexual harassment complaints over the past four years — but just seven of the complaints were substantiated, according to the New York Times. That means only 2 percent of complaints were found to have merit — compared with nearly 17 percent at other agencies citywide.

During a question and answer session with reporters, de Blasio repeatedly said the education department has a cultural problem when it comes to reporting misconduct.

“I can’t parse out for you who was sincere and who was insincere and what type of offense,” de Blasio said. “I can’t get there. I can tell you the fact it’s unfortunately a part of the culture of an agency that is changing that we need to address.”

De Blasio quickly tried to walk back some of his comments on Twitter.

The mayor’s comments come as activists worldwide have raised awareness about sexual harassment, sparking the #MeToo movement. One element of that conversation has been the  importance of taking harassment claims seriously instead of dismissing them. More than three-quarters of the city’s teachers are women, according to the Independent Budget Office.

De Blasio’s responses drew sharp criticism from Michael Mulgrew, president of the city’s teachers union. “Our teachers have a tough enough job that they don’t have time to make frivolous claims,” he said in a statement.

Schools Chancellor Richard Carranza, who was accused of gender discrimination when he was a top school district official in San Francisco, said the education department has increased the number of investigators who look into such complaints.