BANGKOK (AP) — Coronavirus cases continue to rise rapidly in Tonga, and tests have confirmed that the particularly contagious omicron variant is behind the isolated Pacific island nation's first community outbreak since the start of the pandemic, officials said Thursday.

Health Minister Saia Piukala told reporters that 31 more people had tested positive for the virus, nearly doubling Tonga's active cases for the second day in a row to a total of 64, the online Matangi Tonga news portal and other media reported.

While the number may seem small, the nation of 105,000 had managed to escape thus far without any infections aside from a single case brought in from a missionary returning to Tonga from Africa last October, which was successfully isolated.

But with the deliveries of critically-important international aid following the Jan. 15 eruption of the massive undersea volcano and a resulting tsunami, two dock workers tested positive at the start of last week for COVID-19.

Despite efforts to contain the outbreak, it has been spreading and is now being reported in more areas, Piukala said.

Five tests that had been sent to Australia for analysis confirmed it was the omicron variant of the virus, he said.

Three people were confirmed killed in the eruption and tsunami, and several small settlements in outlying islands were wiped out. A thick layer of volcanic ash also blanketed the main island and tainted much of the drinking water, and may have damaged crops.

The only fiber-optic cable to the island was severed in the eruption, making communications sporadic, at best. With several areas now in complete lockdown, the Education Ministry has started home schooling with teachers giving lessons over FM radio.

The Red Cross and other health authorities have warned that as Tonga tries to deal both with the aftermath of the natural disaster and the coronavirus outbreak, its fragile health care system risks becoming quickly overwhelmed.

At the same time, Tonga's isolation — which helped protect it from the virus for more than two years — is now a liability, making it more difficult to provide outside assistance.

In a sign of hope, however, Piukala said all of the latest cases have so far only reported mild symptoms, and that all were vaccinated except for the children.

He did not say how many children were affected.

Tonga's vaccination program had already been doing well, but the current outbreak has led thousands of people to turn out for their first shots or boosters.

As of Wednesday, 98% of the country's eligible population, aged 12 and up, have received at least one dose and 88% are fully vaccinated. More than 67% of Tonga's total population has been fully vaccinated, according to the Health Ministry.