There are 31 new cases of Covid-19 in managed isolation since Thursday.
There are no new cases in the community. Nineteen cases at the border are now linked to the rapidly-spreading UK strain of coronavirus.
"The number of cases reinforces the need for ongoing vigilance at the border, as Covid-19 continues to accelerate overseas," the Ministry of Health said.
International mariners
There are 11 new cases linked to a group of international mariners.
"Only three of these cases have been identified as current cases, while the majority (eight) have been identified as historical cases. A total of 190 mariners arrived on Wednesday and are staying at managed isolation and quarantine facilities in Christchurch," the ministry said.
"A number of mariners were not able to board flights to New Zealand after testing positive during pre-departure testing.
The managed isolation and quarantine facilities have strengthened procedures and protocols to ensure the risk to others in the group and in the facilities is reduced."