Two people have been killed in Fiji since torrential rain flooded large parts of the main island, Viti Levu.
Police say a farmer has been swept away while trying to save his pigs outside Lambasa.
Another farmer drowned on Monday as he also tried to rescue his livestock.
More than 700 people have been evacuated from their homes.
The acting Director General of the Fiji Red Cross Society, Christopher Ho, has told Radio Australia evacuation centres have been set up in some communities to assist those effected.
"There are 32 evacuation centres that are currently open, but as the situation goes there's more being opened," he said.
"We are also doing things on our own...our branches are all on red alert and standby.
At this particular point there is a risk in terms of sending our volunteers out when you have water-clogged roads and the minute we see there is some safe access we will be going out and doing our own assessments as well."
The Fiji Weather Bureau says the Nadi River burst its banks late on Tuesday, raising concerns about flooding in the tourist area of Denarau.
Denarau is built on man-made islands near the mouth of the flooding Nadi River.
Officials say the army has been called in to help tourists reach Nadi airport.
Australia's Department of Foreign Affairs and Trade says Nadi is under water and has warned Australians in Fiji to exercise safety precautions.
Fiji Weather Office forecaster Sanjay Prakesh says a flood warning remains in place for the entire Fiji group, with more heavy rain expected.
"Currently, we have an active trough of low pressure that is hovering over the Fiji Group and there's periods of heavy rain being experienced in Viti Levu at the moment and it's going to happen overnight as well," he said.
- Australian Broadcasting Corporation
- © ABC