No classes were held for students at Mamaroneck High School Monday after a threatening message was discovered in a corridor.

The school's director of facilities discovered the threat near the gymnasium between 6 and 7 a.m. School administrators were notified, leading to the decision to cancel classes and all after-school activities. Police, along with the bomb squad, swept the area but found no real threat.

"This is not something that is characteristic of our students of our community. We are very concerned about it," said Mamaroneck Superintendent Paul Fried. "We consider this a very serious matter."

The school is expected to reopen Tuesday. School officials say they are looking into installing security cameras as a result of the incident.