Hurricane Melissa is forecast to become a rare category five storm as it turns towards Jamaica, bringing life-threatening flash flooding and landslides.

The cyclone, which had winds of up to 120 mph (195 km/h) as of 06:00 GMT, is currently turning north-west in the Caribbean and is expected to make landfall by Tuesday, according to the US National Hurricane Centre (NHC).

It warns of power cuts and damage to infrastructure as Melissa brings up to 30 inches (76cm) of rain and sea level surges as high as 13ft (4m) above ground. "Seek shelter now," residents have been told.

Melissa is the 13th hurricane in this year's Atlantic season, which typically ends in November.

A category five hurricane is the strongest type, with winds of at least 157mph.

While Melissa is set to weaken to a category four before reaching Jamaica, the NHC said there was "very little practical difference in the overall impacts" upon landfall, and that the hurricane will be "at least that intensity" when it hits the island.

With tropical storm-strength winds and rain already expected well before it passes over central Jamaica - including potentially the capital, Kingston - it warns that "preparations should be rushed to completion".

"A multi-day period of damaging winds and heavy rainfall have begun and will cause catastrophic and life-threatening flash flooding and numerous landslides," the meteorological agency urged residents.

Jamaican Prime Minister Andrew Holness said: "I know that there are many Jamaicans who are anxious, who are very concerned, and rightfully so: you should be concerned.

"But the best way to address anxiety and any nervousness and concern is to be prepared."

Residents are being told to secure their homes with sandbags and wooden boards, and to stock up on essentials.

Warnings are also in effect parts of Haiti including the capital, Port au Prince, the Dominican Republic and eastern Cuba, where Melissa is anticipated to bring similar effects by the middle of next week.

Landslides already being caused by the hurricane have already killed two in Haiti, the nation's Civil Protection agency has said.

Melissa is forecast to pass over Cuba by Wednesday before moving through the Antillas Mayores and out into the Atlantic.

By the time it reaches Cuba, it is predicted to have weakened to a category three storm.

While it is hard to link individual weather events to climate change, scientists say it is making weather phenomena more common and more severe.

Warmer oceans produce more moisture in the air, helping fuel the formation of hurricanes.

Ahead of the start of this year's Atlantic hurricane season, the US National Oceanic and Atmospheric Administration predicted above-normal activity, citing warmer seas and potential stronger monsoon activity around West Africa - where Atlantic storms often form.