Exactly one year after New Zealand recorded its first coronavirus case, the country's biggest city, Auckland, has woken up to a second lockdown this month as health authorities try to rein in a cluster of the more contagious UK variant.

The seven-day lockdown of the city of nearly two million people, announced late on Saturday by Prime Minister Jacinda Ardern, was prompted by the case of a person who had been infectious for a week but had not been in isolation.

“It is more than likely there will be additional cases in the community,” Ardern told a televised news conference, although there were no new cases recorded.