A family of four from Vaini and two individuals from Pili were tested positive and have been quarantined.
Prime Minister Hu'akavameiliku told media that road checkpoints have been set up, requiring anyone entering or leaving the villages to be tested.
"Efforts are underway today to contain and test everyone in Vaini and everyone in Pili, to understand the circumstances and the spread of the virus in these towns, according to these four and two new cases that have emerged," he said.
There are now 13 Covid-19 cases in Tonga.
