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 Monday. More than 2,200 tests have been done since Friday, the statement said.
Samoa and several neighboring Pacific island nations were among the last places in the world to avoid virus outbreaks. But the more transmissible omicron variant has changed the equation, and one by one the island nations have been succumbing to COVID-19.
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% of all Samoans have had at least two doses of a coronavirus vaccine, according to Our World in Data.
Samoa has had previous virus 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.