Seven new locally transmitted coronavirus cases have been recorded in New Zealand, as the country attempts to contain a new outbreak after weeks of being virus free.

According to Ashley Bloomfield, the country’s Director-General of Health, six of the new cases were related to a known cluster in Auckland, while the origins of one case remain under investigation — although he was confident that case would also linked to the same cluster.

The total number of cases related to the Auckland cluster stands at 37, Bloomfield said.

Fifty-four close contacts of those infected have been moved to quarantine centers. So far, 24 of them have tested positive for the coronavirus.

It remains unclear where the latest outbreak originated. New Zealand Minister of Health Chris Hipkins said the country has not seen “any positive tests from our border and managed isolation facilities over the last few days, and genome sequencing does not match any of the known cases in these facilities.”

Testing of borders staff — those who work at managed isolation centers, airports, and maritime staff — has been carried out in a bid to find out where the virus may have come from, after local transmission was stamped out for 102 days earlier this year.

Since August 12, New Zealand has implemented an aggressive testing policy, completing 49,780 tests in three days. On Friday alone, 23,846 tests were processed.