The Seychelles, which has fully vaccinated over 60% of its population against Covid-19, is bringing back restrictions amid a rise in cases.
The archipelago of nearly 100,000 people recorded close to 500 new cases in the three days to 1 May and has about 1,000 active cases.
A third of the active cases involved people who had had two vaccine doses, the country's news agency said.
The rest had either had a single dose or were unvaccinated.
Schools have been closed and sports activities cancelled for two weeks. Bars, restaurants and shops are to close early and some gatherings have been banned.
"Despite all the exceptional efforts we are making, the Covid-19 situation in our country is critical right now with many daily cases reported last week," Health Minister Peggy Vidot told a press conference on Tuesday.
More than four-fifths of the active cases were among Seychellois people, with the remainder made up of foreigners.
The Seychelles, which relies on tourism for much of its income, began vaccinating its population in January using Chinese-made Sinopharm vaccine doses donated by the United Arab Emirates.
By mid-April about 60% of the vaccine doses administered in the country were Sinopharm, with the rest Indian-made AstraZeneca vaccine doses, Bloomberg reported.
Trials in China and the United Arab Emirates have put Sinopharm vaccine efficacy at 79% and 86% respectively.
The World Health Organization is expected to approve the Sinopharm vaccine and other Chinese-made vaccines for use later this week.
In April, China's top disease control official said the efficacy of the country's Covid vaccines was low, although he later insisted his comments had been misinterpreted.
Researchers in Brazil have put the efficacy of another Chinese-made vaccine, the Sinovac vaccine, at 50.4%.