People in Jamaica are bracing for the impact of Hurricane Melissa, which is forecast to unleash destructive winds and bring catastrophic flooding to the Caribbean nation in the coming hours.

Melissa was upgraded to a category five hurricane - the maximum strength - early on Monday, the US-based National Hurricane Centre (NHC) said. The authorities fear that Melissa, which has already been blamed for the deaths of four people on the island of Hispaniola, could become the strongest hurricane ever to hit Jamaica.

The Jamaican government has ordered evacuations for parts of the capital, Kingston, and the entire island has been classed as "threatened".  An update from the NHC at 12:00GMT said that Melissa was about 135 miles (220km) southwest of Kingston, Jamaica.

It has maximum sustained wind speeds of 160mph (260km/h) and could strengthen further in the next 12 to 24 hours, forecasters warned. If it continues on the forecasted track, its core was expected to move near or over Jamaica tonight, as well as across south-eastern Cuba, and across the south-eastern Bahamas.

The storm is particularly slow moving, which makes it very dangerous in terms of expected rainfall amounts. According to the NHC, 40 inches of rain (100cm) are possible in parts of Jamaica over the next four days.

Jamaica's Prime Minister Andrew Holness has ordered the immediate evacuation of several vulnerable communities across the island, with officials also urging residents in low-lying and flood-prone areas to seek shelter in safer areas. The country's Minister of Local Government, Desmond McKenzie, told local media that all of the island's 881 shelters were open.

At least three people are known to have died and hundreds of homes have been flooded in Haiti as Melissa brought torrential rainfall to the island of Hispaniola. In the Dominican Republic, located on the eastern side of Hispaniola, one person also died.

Several people were rescued after being trapped in their cars by the rising floodwater.