Samoa has reported scores of new COVID-19 cases each day since detecting its first case of community transmission last week.
The South Pacific island nation of 200,000 people has been in lockdown since Saturday as it deals with its first outbreak of the pandemic.
The outbreak was discovered when a woman who was about to travel tested positive on Thursday and indicates the virus likely had been spreading undetected for days or even weeks.
Samoa reported another 95 new cases in 24 hours to Saturday and another 85 on Sunday.
Only 15 of the 196 active cases were imported from overseas, according to the the latest government statement available on Monday. More than 2200 tests had been done since Friday, the statement said.
Samoa and several neighbouring Pacific island nations were among the last places in the world to avoid outbreaks. But the more transmissible Omicron variant has changed the equation, and one by one the island nations have been succumbing.
Since the start of the year, Kiribati, Tonga, the Solomon Islands, the Cook Islands and American Samoa have all experienced their first big outbreaks.
All Samoan schools are closed, public gatherings are banned, and all stores and other services are shut down, except those considered essential.
The lockdown is initially scheduled to last until Tuesday but many expect it will be extended.
About 65 per cent of all Samoans have had at least two vaccine doses, according to Our World in Data.
Samoa has had previous scares and lockdowns after returning plane passengers tested positive while isolating, but had managed to avoid any community outbreaks until now.
Micronesia, the Marshall Islands and Nauru are among the few remaining Pacific island nations to have avoided Omicron outbreaks.