An Orthodox Jewish high school on Long Island, New York, was evacuated after receiving a faxed bomb threat.

Leaders of the Hebrew Academy of the Five Towns and Rockaway reported Wednesday’s threat to the upper school in Cedarhurst in a letter to the school community posted on its Facebook page. The message said a bomb had been planted on school property.

Following protocol, the school notified police and evacuated the building, taking the students to a nearby synagogue.

A police K-9 unit inspected the building and did not find any explosive device. The building was cleared and evening activities on the campus took place as usual, the letter said.

Police are investigating to find out who sent the letter.

HAFTR’s program, from preschool to high school, is located in three buildings.