The Tongan Government has announced that the main island Tongatapu will go into lockdown from midnight after the discovery of the first case of Covid-19 in the Kingdom last week.

The island, where most of the population live, will going into lockdown from one minute past midnight tonight. It will stay in place until next Sunday.

RNZ Pacific's correspondent in Tonga, Kalafi Moala, said businesses like the banks, the market and other essentials will stay open.

But he said the limits on gatherings are strict.

"In terms of gatherings this is the most significant part of the lockdown. No schools, all schools are closed, no church gathering, no kava club, no entertainment or any kind of gathering," he said.

"For funerals you are allowed ten people inside the house and 20 outside, but it seems to me the restrictions are very much applied to gatherings of any kind."

Kalafi Moala said there are to be no alcohol sales.

Meanwhile he said the infected person who arrived on a flight from Christchurch last Wednesday remains asymptomatic, which the chief executive of health, Dr Sialo Akau'ola, has put down to the impact of the vaccine - the person is double vaxxed.