All Havelock North schools have now closed because of the gastro outbreak.
Lucknow School, Te Mata Primary, Havelock North Primary, Havelock North Intermediate and Havelock North High School closed yesterday after an emergency meeting among the Ministry of Education, principals and board chairmen.
"We issued a blanket closure warning families we will not be open Tuesday or Wednesday," Te Mata principal Michael Bain said.
They made the decision based on the increased number of students and staff who had fallen ill. Fifty per cent of their school roles were absent.
"We had 160 children away and were still sending more home," Lucknow principal Paul Grundy said.
Havelock North High School had just 45 per cent of their school present and principal Greg Fenton said a high number of staff were affected.
"We were struggling to find the right number of staff to take the students," he said.
Havelock North Primary School principal Nick Reed was also absent yesterday after catching the bug.
"I came down with the illness over the weekend but had begun to feel a lot perkier today," he said.
Three hundred children were not at the primary school yesterday and 33 were sent home during the day.
Mr Reed said he had never seen anything like it before.
"We are used to flu epidemics which knock off 20 students but nothing like the numbers that were away yesterday."
The state schools will reassess the situation tomorrow afternoon and hope to be "back on deck" by Thursday morning.
Hereworth School also made the decision to close until Thursday posting on its Facebook page that it had been advised to shut by the Ministry of Education. Iona College and Woodford House remain closed since shutting their doors on Sunday afternoon.
Woodford House has extended the closure until tomorrow.
"The board's responsibility is to ensure the school is sufficiently resourced for teaching and learning," principal Julie Peterson said.
The school had 96 students and 10 staff absent, which was a third of their school role.
"With many of our staff affected by the health issue, we are unable to meet that requirement," Mrs Peterson said.
Kindergartens in Havelock North were also closing, with Te Mata Kindergarten shut today and tomorrow.
Parents and caregivers are advised to check schools' websites and social media to keep informed for the remainder of the week.