The tiny Pacific nation of Palau reported its first cases of coronavirus Saturday, losing its prized status as one of the world's few Covid-free countries as authorities appealed for calm.
Two travellers, who tested positive after arriving from Guam, have been placed in quarantine along with their known contacts.
"We urge everyone to remain calm," the Ministry of Health said in a statement after deciding against imposing lockdown measures.
With more than 80 percent of the 18,000 population fully vaccinated, President Surangel Whipps insisted the remote island state "has been Covid-free but is now Covid-safe".
Until Saturday Palau was just one of fourteen countries in the world that had recorded no virus cases at all, according to the World Health Organization.
The Health Ministry would not say how many contacts were in isolation but a spokesman told AFP they did not believe there had been any community transmission.
Whipps added if anyone who has been fully vaccinated does become infected "it will be just like a flu or they won't show symptoms at all."
The infected travellers tested negative 72 hours before departure but were positive when they had a compulsory test five days after arrival.
Palau protocols demand that in the first five days after arriving, people wear masks and avoid crowds.
The country is not able to determine which strain of the coronavirus the new cases are and a sample has been sent to the United States for analysis.
Palau, situated about 1,000 kilometres (600 miles) east of the Philippines, was one of the few countries to avoid Covid-19 after closing its borders early in the pandemic, despite the huge cost to its tourism-reliant economy.
Most of the other countries on the WHO's virus-free list are also small island nations in the Pacific, bar North Korea and Turkmenistan -- both of whose assertions of zero cases have long been doubted by analysts.
In an attempt to kickstart its tourism industry, Palau opened a quarantine-free travel bubble with Taiwan in April.
It closed a month later when Taiwan experienced a spike in virus cases and reopened last week with any unvaccinated tourists jabbed on arrival.
A Covid-19 case that was reported in Palau in May is no longer listed by the WHO because the symptoms detected were considered historical and posed no transmission risk.