Tropical Cyclone Yasa made landfall in Fiji overnight - with powerful gusts reaching up to 350km/h near the eye of the storm.
Photos and footage of the damage are starting to appear online, as Fijians wake up to the devastation left behind - with reports of houses flattened, trees ripped out of the ground and roads flooded.
There have been no reports of any casualties.
KKU The Fijian Artist posted a series of photos from his brother based in the Bua province - located in the west of the northern island of Vanua Levu, which was hit overnight.
"Big bro just (messaged) finally...thank God he is ok. Sent this in from Nabouwalu, Bua."
'Every single home was obliterated'
Local journalist and correspondent, Lice Movono, said initial reports indicated mass devastation in the north.
"The words I'm hearing are 'absolutely terrifying, never seen anything like it before, it was so long and just so ferocious'," she told NewstalkZB.
"What I'm hearing is that the winds lasted for quite a while. it moved slowly as it was making landfall.
"I've heard of entire yachts disappearing from the harbour...and just trying to verify reports that in some villages, every single home was obliterated."
Early this morning, the Fijian weather authority said a hurricane warning remains in force for half of Vanua Levu, Taveuni and nearby smaller islands including Yacata, Nayau, Vanuabalavu, Lakeba and Moce.
Storm warnings are still active for the western part of Vanua Levu, Cikobia and the rest of the Lomaiviti group.
Gale, strong winds, storm surges and "damaging heavy swell" warnings all still remain in force also.
Locals are also being warned of potential floods and there are flash flood warnings in place for low lying areas also.
In its current state, weather experts say the eye of the cyclone is expected to have average winds up to 205km/h and momentary gusts to 285km/h.
It is now moving southeast at about 22km/h and is expected to be located near the Lau group about 9am local time.
The latest information issued by the Fiji Meteorological Service just before 11pm local time (shortly before midnight NZT) said Koro island was now experiencing gale-force winds.
Gusts of up to 109km/h were recorded at 9pm local time on the island - which has a population of just under 4000 people.
"It will soon start to experience hurricane-force winds," the Fiji Met Service said.
Maps now indicate that the cyclone is moving away from Fiji and towards New Caledonia and even getting close to New Zealand.
Despite last night's powerful winds and the storm around them, locals hunkering down have stayed positive - with photographs of smiling police officers getting people to shelters and videos of children singing throughout the night.
One video, posted on Twitter by Alisi Lutu, showed dozens of people on mattresses on the floor in a room - the children clapping and singing.
"About six families sheltering here," Lutu said.
"Spirits are high and positive as we look to our heavenly father to take us through the night. Pray for Fiji."
A state of natural disaster has been declared in Fiji and the nation has been told to prepare for incredibly strong, "damaging and destructive" winds.
A timeline of events last night
Cyclone Yasa made landfall over the province of Bua around 6pm, said the Fiji Meteorological Service (FMS).
The cyclone centre was expected to be about 25km west-northwest of Koro or about 130km northeast of Suva by 11pm.
Extremely rough seas are expected with waves reaching heights of 14m or more.
Prime Minister Frank Bainimarama says Cyclone Yasa could quite easily surpass the disastrous effects of Cyclone Winston in 2016.
Winston destroyed multiple villages, killed 44 people and left thousands homeless. It caused about US$1.4 billion ($1.95b) worth of damage.
Bainimarama assured Fijians authorities stood by ready to deploy immediately.
"All those in the path of this storm rest assured, we will reach you," he said. "Our battle-tested disaster officials are ready to come to the aid of affected communities.
"Stay safe, Fiji."
State of emergency, curfew in place
The state of natural disaster will be in place for the next 30 days, the nation's disaster management announced.
The average wind speed around the storm is 250km/h, with gusts surging higher than
In a Thursday evening update, the Fiji Meteorological Service said category-five cyclone Yasa was passing through Yasawa-i-Raw and heading towards Fiji's second-largest island, Vanua Levu.
MetService New Zealand meteorologist Angus Hines said the "thick" of the storm will come overnight and into Friday morning,
He said it was also possible areas of Fiji would suffer flash-flooding and coastal inundation, where large waves, strong winds, and low atmospheric pressure would push the ocean much further inland than it would normally reach.
A string of weather warnings remain in place for different parts of the country, the FMS said.
A storm surge and damaging heavy swell warnings are in place for Rotuma, the Yasawa and Mamanuca groups, Viti Levu and Vanua Levu.
A flash-flood warning remains in force for low-lying areas, and landslides are likely, it said.
A curfew is in place from 4pm to 6am.
Sigatoka-based New Zealander Mandy de Vries, who runs tourism business EcoTrax with her husband, spent yesterday "battening down the hatches" and putting up hurricane covers at her home and workplace sites.
Yesterday evening she described the intense heat.
"Before a cyclone, the air gets so heavy and it feels like you can't do anything without sweating. It's been like that for a couple of days.
"The air is so hot. You can't get away from it. It's horrible. It's really intense. You know something's happening. You can feel it in the air."
Casey Quimby, an American who has lived in Fiji for 14 years, said she is "prepping for the worst-case scenario".
She runs Animals Fiji, a shelter and veterinary charity, and is expecting to be busy tending to injured animals in the aftermath of the cyclone.
The team have boarded up the windows at their Nadi and Savusavu sites, and vets have taken medical kits home with them in case they encounter animals in need.
The National Emergency Operation Centre has been activated to co-ordinate the Fiji Government's response and relief efforts.
Evacuations have already taken place in low-lying areas and all non-essential government workers have been told to stay home during the height of the cyclone.
The National Disaster Management Office this morning reiterated warnings of imminent danger, pleading with those living near the coast to move to evacuation centres as the storm approaches.