Less than three months after part of a Jewish school in Kiev, Ukraine, went up in flames under suspicious circumstances, vandals apparently threw stones through the windows of two of its classrooms and an on-site synagogue.

Rabbi Gavriel Gordon discovered the damage Saturday night as he was locking up the Simcha School, a Chabad-Lubavitch day school serving 600 students from kindergarten through post high school.

According to officials, no one had heard anything. The guard had seen a few youths hanging around the school's fence earlier in the day, but had asked them to leave.

The building had been full of visitors over Shabbat, many of them in town for a local wedding that happened earlier in the week. Rabbi Mordechai Levenhartz, principal of the school, suspects that the damage occurred some time after the last Shabbat guest left.

"Thank G‑d, everyone had left the building," said Levenhartz.

Back in October, the school's entranceway was heavily damaged in a suspected arson with anti-Semitic overtones.

This time, Levenhartz said that he plans to reassess the building's security. First on the list, he said, are more cameras and a stronger fence to enclose the school's 500 square meter yard.

"The security of the people and the children is of utmost importance," said the principal.