Tropical Storm Sandy gained strength in the southern Caribbean, and was expected to reach hurricane strength as it swirled toward Jamaica, the US National Hurricane Centre warned.

“Strengthening is expected during the next 48 hours and Sandy is forecast to be a hurricane when it approaches Jamaica on Wednesday,” the Miami-based centre said.

At 1200 GMT, the storm was about 525 km south-southwest of Kingston, packing top sustained winds of 75 kilometers per hour and moving north-northeast at six kilometres per hour, the centre said.

“The center of Sandy will move near or over Jamaica on Wednesday and approach eastern Cuba Wednesday night,” the centre added.

After dumping 12-25 cm of rain on Jamaica, “these rains may produce life threatening flash floods and mudslides,” the center warned.