Murray's Bay Primary School on Auckland's North Shore has been evacuated after receiving a threatening email.
Staff and students have been taken to the gymnasium at Murray's Bay Intermediate School and families are asked to pick their children up from the entrance on Sunrise Ave.
The school will be closed for the rest of the day.
Police have told the school it will take some time to deal with the incident.
Browns Bay School has also closed "due to the threat".
People were asked to stay away from school grounds, a statement on the school's website said.
Sherwood School has closed and said this was due to a "bomb threat we received via email".
In a statement, police said they were making enquiries into emails of a concerning nature directed to a number of organisations in Tāmaki Makaurau today.
"We are working to establish the origin of the emails and have yet to establish any actual threat to any organisation.
"Staff are working with those impacted and each organisation may respond differently according to their individual circumstances and the information available to them."
They would not disclose the names of individual organisations that received the emails.