Tropical Cyclone Evan is photographed by NASA's Aqua satellite as it passes over Samoa on December 13, 2012
Fijian authorities scrambled to evacuate tourists and residents in low-lying areas Sunday as a monster cyclone threatened the Pacific nation with "catastrophic damage" after causing devastation in Samoa.
At least four people were killed when Cyclone Evan slammed into Samoa and the toll was expected to rise with a search launched for eight men missing on three fishing boats.
Only one survivor has been found, said the New Zealand Rescue Co-ordination Centre, which is overseeing the search.
After crossing Samoa, Evan intensified as it ploughed through the Pacific and forecasters said destructive winds could reach nearly 300 kilometres per hour (186 miles per hour) by the time it hits Fiji early Monday.
Government officials fear it could be as devastating as Cyclone Kina, which killed 23 people and left thousands homeless in 1993.
Squally thunderstorms were expected to flood low-lying areas while coastal villages were at risk of sea flooding, authorities said.
The international airport at Nadi was packed as 850 tourists were removed from luxury resorts on outlying islands,
"The safety of the tourists was paramount," said Fiji Tourism and Hotel Association managing director Dixon Seeto, but with most flights booked the holidaymakers had little chance of getting out before the storm.
Fiji's main airline Air Pacific either cancelled or rescheduled its Monday flights while other airlines said they were closely monitoring the situation..
Philip Duncan, head analyst with the WeatherWatch.co.nz meteorological service, said Fiji faced the prospect of flash flooding and mudslides.
"Gusts may end up climbing to 280 kilometres per hour or greater around the centre of Evan," Duncan said.
"Some small, low-lying communities and resorts may suffer catastrophic damage and some small islands may be entirely submerged as the storm and storm surge roll by."
More than 200 evacuation centres have been opened and Information Ministry permanent secretary Sharon Smith-Johns said people at risk should move.
"People living in low-lying areas should consider moving to higher ground or evacuation centres," she said.
Fiji's military leader Voreqe Bainimarama has warned the storm is an "impending disaster" and offers of international aid have already been received.
Australian Foreign Minister Bob Carr said Canberra was offering financial assistance as well as expert personnel and supplies.
The cyclone is expected to hit the northern part of Fiji early Monday with strong winds and heavy rain striking several hours earlier, said Nadi Weather Office duty forecaster Amit Singh.
"The cyclone is not going to slow down. It is intensifying," he said.
Meanwhile, it could be some days before the full extent of the damage in Samoa is known because of the difficulty reaching outlying islands.
About 4,500 people remain in emergency shelters after Evan destroyed houses and damaged electricity and fresh water supplies, Samoan officials said.
Prime Minister Tuilaepa Sailele also warned of possible food shortages next year because crops were destroyed.
The New Zealand Air Force and Tahiti search and rescue authorities were scouring the ocean for the fishing boats missing in rough seas.
New Zealand search coordinator Tracy Brickles said the 30-year-old skipper of one boat survived and made his way ashore after his vessel tipped over on Friday but there was no information about his crew.
A vessel fitting the description of another boat has been seen washed up on an island but there was no sign of survivors.