An elite prep school in The Bronx says it has to keep the doors to its grade-school classrooms closed and children out Wednesday because too many educators are taking off for a planned “women’s strike” in conjunction with International Women’s Day.

The Ethical Culture Fieldston School in Riverdale sent an e-mail to parents Tuesday night reporting that a “critical number” of female staffers had planned to join Wednesday’s nation-wide walkout — which is being coordinated by the group that initiated January’s anti-President Trump women’s march.

The school — where tuition runs about $47,000 a year — said that while there would be adequate teacher coverage for its middle and high schools, so many lower-grade staffers are opting out that lower classes could not “operate safely.”

Fieldston leader Jessica Bagby wrote, “I am deeply sorry about the impact this protest will have on families at Fieldston Lower, and women in particular, for whom this walkout creates an undue burden and reinforces inequities tied to economic means and job security.”

She said that the higher grades Wednesday will conduct teach-ins on topics related to women’s rights.

Elsewhere in the country, some entire school districts have been forced to shut their doors for the day.

In North Carolina and Virginia, 27,000 students have been told to stay home because of inadequate staffing due to International Women’s Day events.