Fong said the second of Wednesday's new cases is a 25-year-old male who had stayed at the house of the Makoi woman who tested positive to the virus on Saturday.
The two new cases of the B1617 variant of Covid-19 pose a threat never seen before for those on Viti Levu, says Fong.
"We remain in a period of nationwide containment, but these two latest clusters indicate to us that this virus has spread to localities in several different areas of Viti Levu.
"These two weeks will define the next two months for Fiji, and we all need to behave like we have Covid, even if there are no known cases in our community or we are showing no symptoms of the virus."
Fong said Fijians must act to contain the threatening B1617 variant of Covid-19.
This variant has been described as one with worrying mutations that could create major chaos.
The FBC reports medical officials are trying to get people to understand the need to take precautionary measures over the next fortnight, saying otherwise the country faces a severe outcome.
B1617, which has been called a double mutant, has occurred in India, Brazil, South Africa, the UK and the US.