AKIPRESS.COM - A puzzling new outbreak of the coronavirus in New Zealand's largest city grew to 17 cases on Thursday, with officials saying the number will likely increase further, Fox News reported.

And a lockdown in Auckland designed to extinguish the outbreak could be extended well beyond an initial three days.

It was a turnabout from Sunday, when the South Pacific nation of 5 million marked 100 days without any cases of local transmission. For most people, life had long returned to normal as they sat down in packed sports stadiums and restaurants or went to school without the fear of getting infected.

The only cases for months had been a handful of returning travelers who have been quarantined at the border. But then earlier this week, health workers discovered four infections in one Auckland household.

The source of the new infections continues to stump officials. Director-General of Health Ashley Bloomfield said genome testing has not yet matched the new cluster with any infections that have been caught at the border, although the testing has indicated the strain of the virus may have come from Australia or Britain.

Auckland was moved to Alert Level 3 on Wednesday, meaning that nonessential workers are required to stay home and bars, restaurants and most businesses are shut. The rest of the country has moved to Level 2, requiring social distancing.

The government is due to make a decision Friday on whether to extend Auckland's lockdown, which seems increasingly likely given the new cases.