Tonga has gone into a lockdown after several cases of Covid-19 were recorded in the capital city Nuku’alofa.
Prime Minister Siaosi Sovaleni said on Tuesday two port workers had tested positive. Officials later confirmed three more cases in family members.
The South Pacific nation had previously managed to stay virus-free.
The outbreak comes as Tongans try to recover from a deadly volcanic eruption and tsunami which left three dead and damaged homes and infrastructure.
Tonga had avoided Covid outbreaks by closing its borders to the outside world in early 2020.
But since the eruption it has since been heavily dependent on foreign aid for supplies of fresh drinking water, shelter kits and rescue equipment.
So far, foreign aid deliveries there have been handled using contactless protocols to stop the virus spreading from abroad.
They include leaving humanitarian supplies in isolation for three days before they are handled by Tongans.
Australia, New Zealand, the United States, China, France, Fiji and the UK have all sent ships carrying supplies.
In a national address late on Tuesday, Mr Sovaleni confirmed the Covid-19 cases and said Tonga would enter lockdown from 18:00 local time Wednesday, with the situation reviewed every 48 hours.
“The most important issue at the moment is to slow down and stop those who have been affected,” he said, adding that “no boat will be allowed to go from one island to another, no more (domestic) aeroplane flights”.
At least 83% of Tonga’s 106,000 strong population have received double doses of the Covid vaccine. However, the remoteness of some of these island communities, many with limited healthcare resources, makes them particularly vulnerable to an outbreak.