Due to elevated security levels in the wake of recent terror attacks, some high schools in the GTA have decided to cancel planned trips with students to destinations in Europe.

Four separate high schools within the Peel District School Board have cancelled trips slated from now to May 6.

Carla Pereira, a spokesperson with the school board, told CP24 the cancellations were decided by administrators on Tuesday.

Pereira said all students and parents will be issued a refund for the costs they’ve paid thus far.

According to Pereira, the four schools affected are: Woodland Secondary School in Mississauga, Mayfield Secondary School in Caledon, Rick Hansen Secondary School and Lorne Park Secondary School both in Mississauga.

Woodland Secondary School had planned a trip for about 70 students to travel to Czech Republic and Austria this Friday.

Mayfield Secondary School scheduled to travel to Italy on April 15 with 80 students.

Rick Hansen Secondary School planned to take students to Brussels or Amsterdam on April 14.

Lorne Park Secondary School scheduled to travel to France on May 6. Pereira said that this trip was cancelled months ago, in Dec. 2015.

Christina Choo-Hum of York Region District School Board told CP24 that there are trips scheduled for students in the York Region District as well. Choo-Hum said over the next month, students are planning to travel to Italy, Ireland, Austria, Paris, Scotland and England.

She said there is a possibility of cancelling those trips, but a meeting with parents will be held to decide that.

In March, bombs destroyed the Brussels Brussel-Zaventem Airport and a subway station, killing 35 people and wounding hundreds.

In Nov. 2015, gunmen opened fire on six locations in Paris, killing 130 people and wounding 100.

ISIS has claimed responsibility for both attacks.

Brussels is still under a threat level of four, meaning “serious and imminent threat.” The rest of the country is at three.