Miami - Hurricane Paloma strengthened over the Caribbean and was approaching the Cayman Islands and Cuba with sustained winds of 140 kilometres an hour on Friday.

"Paloma is a category one hurricane on the Saffir-Simpson scale. Strengthening is likely and Paloma is expected to become a category two hurricane later today (Friday) and possibly reach category three intensity by Saturday," the Miami-based National Hurricane Centre (NHC) said.

The storm became a hurricane in the Caribbean Sea late Thursday. The NHC said Paloma was moving north and would first hit the Cayman Islands, and was later expected to turn toward the northeast and hit eastern Cuba.

Cuba was struck by two powerful hurricanes, Gustav and Ike, within just seven days between August and September. The island was devastated, with an estimated 9 billion dollars in damages.

Should Paloma make landfall on Cuba, it would be the fifth storm to hit the island this season.

Paloma is the 16th storm in the current season - set to end November 30 - in the Atlantic Ocean. (dpa)