The cyclone hit the tiny island of Cikobia, north of Vanua Levu at about 3 a.m. local time (1500 GMT Friday), flattening everything in its path as the island's 69 inhabitants took shelter in nearby caves.

"All of the 69 villagers on the island are safe and well," said Ami Chand, medical superintendent at the nearby Labasa hospital, who has been in radio contact with villagers on the island.

"Everybody had evacuated early into the caves. That was the saving grace."

Heavy rain continued to fall across Vanua Levu on Saturday, and people across Fiji were warned of possible flash flooding and high seas in coastal areas in the wake of the cyclone.

Vanua Levu, with a population of about 360,000 people, is in the north of the Fiji island chain and has only limited tourism development, unlike the country's main island Viti Levu and its internationally renowned island resorts off the west coast.

Fiji Meteorological Service duty forecaster Matthew Boboterhoven said Cikobia island was in the direct path of the cyclone, which was moving away from land and expected to weaken as it headed out to sea.