CHRIST CHURCH, BARBADOS (REUTERS) - Hurricane Elsa blew roofs off homes, toppled trees and sparked flooding in the island nation of Barbados on Friday (July 2) as the storm was forecast to head towards Haiti.

Minister of Home Affairs, Information and Public Affairs Wilfred A. Abrahams urged Barbadians to shelter in place and only leave their homes if the structures were damaged.

Elsa strengthened into a hurricane earlier in the day and was about 153km west-northwest of St Vincent, blowing maximum sustained winds of 140kmh, the US National Hurricane Centre (NHC) said.

"The island definitely cannot handle any sort of damages at this point because we still haven't recovered from the volcanic eruption yet," said 20-year-old student Queriise Thomas in the community of Choppins in southern St Vincent.

Earlier this year, heavy rains slammed St Vincent with major flooding and landslides after a series of volcanic eruptions blanketed large swathes of the island in a thick layer of ash.

Thomas said intermittent heavy rain caused flooding and parts of the island lost electricity. St Vincent's water and sewage authority cut water supply to all residents as a precaution due to potential mudflows.

The NHC forecast 10cm to 20cm of rain with a maximum of 38cm across the Windward and southern Leeward Islands including Barbados, which could lead to isolated flash flooding and mudslides.

Hurricane conditions were expected in Haiti and possible in the Dominican Republic and Jamaica by late on Saturday, the agency said.

The Barbados minister said damage was reported in the south of the island including power outages, fallen trees, flash flooding and damaged roofs.

Emergency services were unable to reach people, but there were no reports of injuries or deaths.

A resident in south Barbados, 43-year-old structural engineer Greg Parris, said his home lost power around 7am and he saw blown-out roofs and some flooding in his neighbourhood.

"It was scary. Most of us, we haven't experienced anything like this for a while," Parris said.

Elsa's progress should be monitored by the Windward Islands, Leeward Islands, the Virgin Islands, Puerto Rico, the Dominican Republic, Cuba and the Cayman Islands, the Miami-based NHC said.

Little change in Elsa's strength was forecast over the next 48 hours and some decrease in winds is possible on Monday, the hurricane center said.

Elsa's storm surge was expected to raise water levels by as much as 30cm to 120cm above normal tide levels in some areas.

Puerto Rico could receive up to 12cm of rain, the NHC.