TC Yasa

While the cyclone had weakened to a category 1 during Saturday afternoon, the disaster management office confirmed the death toll had risen to four. And it had caused widespread damage since hitting Fiji on Friday, particularly in the northern areas and the island of Vanua Levu.

Save the Children Fiji chief executive Shairana Ali said Kia Island, north of Vanua Levu had "basically been completely devastated".

"Judging by the pictures it looks like it's a warzone. We don't know yet if there are injuries," she said.

The public is being warned to prepare to be hit by a devastatingly severe cyclone with impacts to be felt late Thursday and into Friday.

Cyclone Yasa is a category five storm, packing winds of up to 315 km/h.

Its forecast track has it moving across the main islands of Viti Levu and Vanua Levu as it snakes southeast.

Fiji Met Service forecaster Steven Meke said the public needed to prepare for the worst.

"The impacts will be devastating for Fiji.