Dr Ashley Bloomfield says "immediate action" was taken to shut down three further education facilities after Covid-19-positive students were confirmed.
The Director-General of Health today advised students, parents and staff at Glamorgan School on Auckland's North Shore, as well as Southern Cross Campus and Taeaofou | Puaseisei Preschool, both located in South Auckland's Mangere East, to remain vigilant for symptoms of the virus.
The schools are in addition to Mount Albert Grammar, also in Auckland, which has also confirmed a case of the virus.
"Immediate action was taken with those education facilities last night," Dr Bloomfield said.
"Auckland Regional Public Health is tracing close contacts at the two schools and the preschool, while they do this pupils and their families have been asked to be vigilant for symptoms after one student in each of the two schools tested positive."
Dr Bloomfield also said there were 13 more cases of Covid-19 in New Zealand today, made up of 12 confirmed cases and one probable case.
Two of today's new cases are in Tokoroa, Waikato. They tested positive after being followed up as close contacts of a family member who is one of the previously-confirmed Auckland cases.
Twelve of the cases have been linked to the Auckland cluster but the 13th - the latest case found - is still still being investigated. That person is currently in hospital.
The new figures mean New Zealand has 48 active cases and the country's overall confirmed and probable cases moves to 1602.
Dr Bloomfield also said there was a confirmed case of Covid-19 at Pakuranga College, however the school's principal told 1 NEWS this afternoon he hadn't been made aware of any students with the illness.