St Patrick's College in Wellington has been closed and students and staff sent home following a bomb threat today.
Police are at the Kilbirnie school and working with management, but as a precaution all of the school's 830 students and 100 staff have been sent home for the day.
The school's website says it received an anonymous bomb threat around 10am.
Rector Neal Swindells says the school received an emailed threat that a bomb would explode at the school at 1pm today.
He said there was no indication of a motive for the threat which was the first time the school had received such a message.
He believed it was a hoax and school would re-open tomorrow.
Police say there is no other information available at this time.
The threat follows similar incidents in February which closed a number of schools around the country. At the time, police said the "robotic sounding" phone calls could be linked to an international hoax which had hit the US and other countries.