Hurricane Melissa picked up speed as it churned across open ocean towards Bermuda on Thursday, after wreaking destruction across much of the northern Caribbean, where local authorities have reported almost 30 deaths.
At 5pm (9pm GMT), Melissa was a Category 1 storm 526km south-west of the North Atlantic British island territory, where hurricane conditions were expected by nightfall even as Melissa's eye skirts north-west.
The storm had maximum sustained winds of 169kph.
Residents remained calm as Melissa was expected to give the island a relatively wide berth. Authorities said they would close its causeway on Thursday night and shut schools and ferries on Friday "out of an abundance of caution".
In the Bahamas, which Melissa cut through overnight, authorities lifted storm warnings but did not give the all-clear. An official said authorities expected to decide by Saturday whether it was safe for the hundreds of people who evacuated from affected islands to return to their homes.
Melissa did not directly hit Haiti, but caused at least 25 deaths there, authorities said, mostly in the southern town of Petit Goave when a river burst its banks after days of torrential rain.
A river also caved in and carried off part of a national motorway, local newspaper Le Nouvelliste reported. The road, which had been weakened by last year's Hurricane Beryl, connected to the nearby city of Jacmel.
Melissa was the first major hurricane since 1988 to directly hit Jamaica, where authorities reported at least four deaths in the south-western region site of the hurricane's landfall as a powerful Category 5 storm. Wind speeds were well above the minimum level for the strongest hurricane classification.
US forecaster AccuWeather said Melissa was the third most intense hurricane observed in the Caribbean, as well as its slowest moving, compounding damages for affected areas.
Satellite imagery showed trees and homes devastated in the hardest-hit areas of Jamaica, sparse remaining greenery defoliated and most structures destroyed.
"I know many Jamaicans are concerned about their loved ones," Prime Minister Andrew Holness said in a video message from a helicopter as he headed to hard-hit Westmoreland parish.
Jamaica's military called on reserve personnel to report for duty in relief and rescue operations. More than 70 per cent of electrical customers in Jamaica remained without power as of Thursday morning, said Energy Minister Daryl Vaz, with power lines felled across the island's roads.
Many schools remained without power or water, officials in the capital Kingston said.
More than 130 roads remained blocked by trees, debris and electric lines, authorities said, forcing the military to clear roads on foot into isolated areas, with ambulances following close behind.
One road in the hard-hit coastal town of Black River was swamped with more than 1.2 metres of sand stretching over 1.5km, officials said.
In western parts of the island, people crowded by supermarkets and petrol stations to fill up on supplies.
US search and rescue teams were headed for Jamaica on Thursday to assist in recovery efforts, Jamaican authorities said. Secretary of State Marco Rubio said the US was prepared to offer "immediate humanitarian aid" to the people of Cuba, a long-time US foe.
Authorities in Cuba, which Melissa struck in the night as a Category 3 storm, said they were "awaiting clarification on how and in what way they are willing to assist".
At least 241 Cuban communities remained isolated and without communications on Wednesday after the storm's passage across Santiago province, affecting up to 140,000 residents, according to preliminary media reports.
Residents of Santiago, Cuba's second-largest city, began returning to repair their homes. Authorities had evacuated 735,000 people to shelters outside the hurricane's cone and relocated tourists in small northern islands to inland hotels. Cuba reported substantial infrastructure and crop damage but no loss of life as of midday on Thursday.