Hamilton's Hillcrest High School is being evacuated due to a "threatening note".
In a message posted on the school's Facebook page this morning, Hillcrest High School said it was "currently being evacuated as at 10.50am".
"The office is unattended until further notice. Please DO NOT phone or come to the school as you will not be responded to. We will update details on his page in due course."
One woman has posted on the Facebook post that there has been a "bomb threat written in one of the toilets, we are all on the field and safe, a bomb search squad are coming".
Police told Fairfax staff found a threatening note and police were called about 10am, a police spokeswoman said.
It is understood all the students are on the school field.
Principal Kelvin Whiting said the school's deputy principal was alerted to a note about a bomb threat being written on a wall of a block of school toilets earlier this morning.
The police were notified who told them to evacuate.
After alerting students they were moved outside on to the field - under shade - as a police bomb squad crew investigated.
Parents were alerted by either email or text and a message was later posted on Facebook.