Recent terror attacks in Paris and Brussels are causing some schools in the Netherlands to change their field trip plans, according to a report released Tuesday by the Dutch Broadcast Foundation. Of 100 schools surveyed, a quarter said they were taking new safety precautions for their trips — which sometimes involved moving the destination entirely.

"This year we will not go to capital cities," Wim Krijbolder, a teacher at Pius X College, told the broadcast foundation.

Administrators, parents and students have grown fearful as the Islamic State group has recently upped its presence in Europe. In November, the extremist organization, also known as ISIS, coordinated a massacre in a concert hall and restaurants in Paris that left 130 people dead. Months later, in March, bombings in a Brussels airport and metro station killed 32. Both events sparked international concern about whether some of the continent's most popular cities were safe for travel.

Schools want kids to explore the world, but not in unsafe environments. So some Dutch institutions, like Pius X College, have moved student trips to suburban settings, avoiding hubs like Berlin and canceling excursions to London. Others, like the Roncalli School, have made rules where students cannot take subways or stay in hotels in the city.

"Although you don’t want to give in, you have to use your common sense," Cor Kuijpers, director of the Jan van Brabant College, told the foundation, according to a translation from "If anything happened, you’d never forgive yourself."

Dutch schools aren't the only ones rethinking student trips due to the ISIS threat. At least two schools in Northern Ireland called off their trips to the Euro 2016 soccer finals in France next month, according to the Mirror. This year, the board of education in New Haven, Connecticut, debated whether to stop all overseas trips completely, the New Haven Independent reported. "Err on the side of the kid being disappointed than the kid dying," board member Ed Joyner said at the time.

Security expert Chris Falkenberg, a former Secret Service agent, told Town & Country that students traveling abroad should try to blend in, move through the airport quickly and stay only briefly at landmarks that could be targets. But he also noted the unpredictable reality of terror attacks. 

"I don't think we have any idea what will happen next," he said.