Canada’s largest school board has barred all future field trips to the United States because of concerns that some students could get caught up in President Donald Trump’s travel ban. And a girls chorus in California just became the latest U.S. institution to ditch an overseas trip for the same reason.

The Toronto District School Board wrote in a letter to principals Thursday that its decision was passed unanimously at a meeting held the previous night, amid concerns for protecting student safety and embracing values of equity and inclusion. Trustees also feared that border problems could scuttle trips at the last minute for students who often fundraise for many months to pay for travel.

“We strongly believe that our students should not be placed into these situations of potentially being turned away at the border,” TDSB director John Malloy said in a statement, according to the Toronto Star.

The district “remains committed to ensuring that fairness, equity, and inclusion are essential principles of our school system and are integrated into all our policies, programs, operations, and practices, including school trips,” he added. The district includes nearly 250,000 students in 584 schools.

Some 24 trips already planned will be allowed to go ahead, including an upcoming international business competition in California ― unless there are changes to Trump’s ban, which is currently blocked by a federal court ruling in Hawaii. If any student is held up in any of the trips, Malloy will have the authority to cancel the rest, the Star reported.

School administrators are worried about students who are from nations on the list of six predominantly Muslim countries that the Trump administration targets in the ban.

It’s not just Toronto grappling with the issue in Canada. The superintendent of a British Columbia school district told the Canadian Press that teachers and administrators not only have to consider student safety but “ethical issues” as well. A school board in Windsor, Ontario, last month also canceled all trips to the U.S., including one planned to the Detroit Opera and a Holocaust memorial nearby. The district includes 38,000 students.

A Winnipeg superintendent told the Canadian Press that principals, teachers and students in his diverse district all value inclusivity, and one school’s recent decision to cancel a U.S. trip, while rushed, was “easy.”

“I just can’t imagine that we would get a request from a school principal to approve a trip to the U.S. where students in the group wouldn’t be allowed to go,” he added. “That would be counter to our culture.’’

In the United States, some schools are concerned about students returning to their origin countries after travel abroad. A school in Farmington Hills, Michigan, canceled its annual trip to Stratford, Ontario, this month because of student fears about border problems returning home.

The board of the Grammy Award-winning San Francisco Girls Chorus in California canceled an upcoming trip to Scotland this week because they feared the 40 performers, aged 12 to 18, could be held up at the border.

“We have to look out for every single member of our organization, regardless of what their status may be as a citizen or green card holder or whatever,” executive director Andrew Bradford told NBC News Monday. “We saw some of the challenges other artists and arts organizations were having around the country with international travel, so [the board] deemed it would be best for us not to go.”