School year starts off on an alarming note with multiple incidents involving students across Long Island districts

The school year on Long Island is off to a scary start for parents and students, as at least three districts say they have had to deal with threats or weapons brought to school.

The Sachem Central School District says a Sachem High School North student brought a knife onto a school bus Thursday.

A letter from district superintendent Patricia Trombetta says the student showed the knife to another student at the bus stop.

The district says another student alerted staff and police were called.

Suffolk County police say they are investigating the incident.

A student brought a bullet into Jonas E. Salk Middle School in Levittown, according to a letter from school district Superintendent Todd Winch.

The letter says there were no weapons involved in the incident and there was no threat to the school.

He said all students and staff are safe.

The superintendent says the incident was reported to Nassau County Police.

A 15-year-old Lindenhurst boy was also arrested after police say he threatened to shoot people at Brennan Middle School in West Babylon.