The Fijian Government is still trying to contact areas that haven't been heard from since being struck by Severe Tropical Cyclone Winston on the weekend.
Oxfam in the Pacific Regional Director Raijeli Nicole said communication blackspots were making it very hard to assess damage and determine the scale of the response required.
"The Fijians are desperately trying to repair severed lines of communication, but they hold grave fears that the news waiting for them will be dire," Raijeli Nicole said.
"Given the intensity of the storm and the images we have seen so far, there are strong concerns that the death toll won't stop climbing today and that hundreds of people will have seen their homes and livelihoods completely destroyed."
Severe Tropical Cyclone Winston hit Fiji as a Category 5 storm on Saturday, packing wind gusts at its centre of up to 325kph, with average winds of 230kph.
The Fijian Government has reported seventeen deaths so far. The UN humanitarian agency OCHA reports 150 houses were destroyed and 60 others damaged in the Eastern Division, which includes Kadavu, Lau, Lomaiviti and Rotuma.
"Our main concern is for people in makeshift housing who did not have the protection of well-constructed buildings in urban centres and residents of outlying islands, particularly in the Lomaiviti group," Nicole said.
The Fijian Government is leading the response and has declared a state of disaster.
They issued a curfew for the whole of Fiji, taking effect from 6pm Saturday local time, which was expected to remain in place until 5.30am this morning.
"People seem to have heeded the warnings from the government to prepare themselves and stayed indoors, or in government organized evacuation centers, so we hope this will have kept casualties as low as possible," Nicole said.
A humanitarian response coordinator will be deployed from Australia as soon as flights allow. As the scale of devastation becomes more apparent, Oxfam may deploy more staff from the region and Australia should assistance be required.
Oxfam has expertise in water supply, sanitation and hygiene, emergency food security and restoring livelihoods. And we currently have staff on standby in Australia, Vanuatu, Papua New Guinea and New Zealand.