WELLINGTON (Reuters) – Australia on Thursday extended its suspension of quarantine-free travel with New Zealand, as the Pacific Island nation investigated two new positive cases of the South African COVID-19 variant.

Australian Acting Chief Medical Officer Michael Kidd said the travel pause on green zone flights from New Zealand to Australia was extended until Sunday.

“This allows continuing protection of the people of Australia, while the extent of the situation in New Zealand continues to be clarified,” Kidd told a news conference.

Australia suspended a one-way “travel bubble” with its trans-Tasman neighbour for 72 hours earlier this week after New Zealand confirmed its first case in months on Monday.

Since then, two people have tested positive to the South African variant of the coronavirus, and all cases are linked to the same quarantine facility in Auckland, New Zealand’s largest city.

The new infections come as New Zealand was ranked the best performing in an index of almost 100 countries based on their containment of the coronavirus.

Responding to the news, a New Zealand government spokeswoman said Prime Minister Jacinda Ardern “retained confidence in our systems and processes but acknowledged the decision was for the Australian government to make.”

Under the bubble, travellers were able to arrive in Australia from New Zealand without the need to quarantine though movement in the other direction requires 14 days’ quarantine.

Health authorities on Thursday conducted further tests and began contact tracing efforts on the two new cases in Auckland.

Both cases were returned travellers in hotel quarantine who were released after returning negative tests following their 14-day isolation.

They had stayed at the same hotel at the same time as the first case of coronavirus in the country in over two months that was confirmed on Monday.

New Zealand also said it would tighten rules at quarantine facilities and people will not be able to leave their rooms following their day 12 COVID test, until they depart from the facility.

The country has largely avoided the high numbers of infections and deaths from the virus as seen in many other nations.

The total number of active cases in New Zealand is 69. The country has had a total of 1,943 confirmed cases and 25 deaths so far.

Reporting by Praveen Menon, Swati Pandey and Melanie Burton; Editing by Sam Holmes