Tropical cyclone Ami, which hit Fiji yesterday, has now passed Tonga and is rapidly moving away to the kingdom's southeast.
The Fiji government has declared a state of natural disaster emergency in areas of the north and west of the country hit by the cyclone.
It covers the second island of Vanua Levu, Taveuni and islands in the Lau and Lomaiviti groups.
The declaration of a state of natural disaster will enable emergency powers to be activated to provide assistance to cyclone victims.
While some speak of widespread destruction, details are sketchy because of a breakdown in communications.
Full details of the damage will be known only after an aerial survey today by a New Zealand air force Orion plane.
The New Zealand foreign minister, Phil Goff, says a clearer picture should emerge by midday.
Fiji's domestic airlines will resume all local services and regional flights to Tonga and Tuvalu from today.
Shops, banks and business houses are expected to re-open for normal business except for those which were damaged by flood waters in Vanua Levu and Taveuni.