The mayor of Labasa in Fiji's north says the flooding, which forced more than 600 people to leave their homes, came as a surprise.
The flooding was caused by a depression which passed over Vanua Levu yesterday.
The mayor of Labasa, Charan Jeath Singh, says the met service had not issued a warning about the depression.
"There has been a major damage in town and it has taken a lot of people by surprise. We are now basically seeing people cleaning up and trying to retrieve whatever has been left."
Mr Singh says about ten evacuation centres have opened overnight to give shelter to affected residents, but they lack the basic necessities, such as fresh water and blankets.
The interim prime minister, Commodore Frank Bainimarama, has reportedly instructed the minister of finance to assess the situation.
