Hamas barred a group of children from entering Israel on a goodwill trip earlier this week.

Intended as a “postwar conciliatory trip meant to foster peace,” 37 children were to meet the Palestinian president and members of Jewish and Arab communities in Israel, and even to visit an Israeli zoo. According to the Associated Press, many of these children have lost a parent during the conflict between Hamas and Israel.

But when the bus full of children and their chaperones approached the Israeli border, it was turned away by Hamas.

Hamas spokesman Eyad Bozum told the AP the decision was made “to protect the culture of our children and our people” from Israel.

Bozum claimed that Hamas would make sure a conciliatory trip “will never happen again.”

Yoel Marshak, one of the trip’s Israeli organizers, told the AP that the visit “was meant to a show a positive side of Israel and promote peace.”

“These children will one day be the leaders of Gaza, and they would have remembered this trip and known that we can live in peace, side by side,” said Marshak.

Marshak said he obtained “written approval” for the trip weeks ago from Hamas and that he was “surprised” the children and their chaperones were barred entry. He hopes to reorganize the trip.

Abu Luli, a 13-year-old Palestinian boy who recently lost his father in “an electrical accident,” said he was “disappointed” he was not permitted to visit Israel.

“I was very happy that I will go and was saddened when we were prevented,” Luli told the AP.

This summer, Israel and Hamas fought a 50-day war that claimed more than 2,000 lives.