PORT-AU-PRINCE - Hurricane Dean bore down on Jamaica early Sunday amid concerns it could become "a potentially catastrophic" category five storm capable of causing death and widespread destruction.

Tourists fled resorts in the path of the storm and island residents battened down as the massive swell skirted the Dominican Republic and plowed towards Jamaica, the Caymans and the Mexican coast.

A boy of 16 was reported dead and several injured in the Dominican Republic as Dean swept by to the south, sending great waves crashing onto its shores, the governor of eastern Santo Domingo province Eladio Martinez said on radio.

Haiti ordered flights and coastal shipping suspended through Sunday and prepared to evacuate seaside regions in Dean's path as the storm appeared poised to pass next to the country at midday Sunday.

Jamaica, dead at the center of the storm's expected track, went on full alert, closing down airports, as hundreds of thousands flocked to markets and petrol stations to stock up on essentials.

"Dean could become a potentially catastrophic category five hurricane at any time before it reaches Yukatan," the US National Hurricane Center warned in a statement issued in Miami, Florida.

Category five hurricanes can bring huge storm surges of 5.5 meters (18 feet) or more and can require the massive evacuation of areas as far inland as 10 kilometers (six miles).

At 0600 GMT, Dean was churning 295 miles (480 kilometers) east-southeast of the Jamaican capital of Kingston and 155 miles (245 kilometers) south of Port-au-Prince, packing sustained winds of 145 miles (230 kilometers) per hour, according to the NHC.

Moving west-northwest at 17 miles (28 kilometers) an hour, it was forecast to pass south of Haiti overnight and reach Jamaica later on Sunday.

It was also on direct course for the Cayman Islands and then forecast to move to the resort region of northern Yucatan.

In Jamaica, Prime Minister Portia Simpson Miller called on all off-duty police officers, firefighters and prison warders to report for work in an effort to reinforce security and rescue operations.

Curfews of 48 hours were imposed in a number of areas, mandatory evacuation of low lying and flood prone areas was ordered, and the country's two main airports in Port-Au-Prince and Montego Bay were closed.

Jamaican television showed long lines at gas stations and empty shelves in super markets as consumers prepared for what could be days of heavy rain.

Also on Saturday the White House said it was ready with aid for Jamaica if needed in the wake of the hurricane.

In Cuba just to the north, authorities began evacuating tens of thousands of people in six eastern provinces to save them from possible flooding and destruction as the storm sweeps by.

The civil defense authorities said 35,000 people were targeted by the evacuation order in the southeastern province of Holguin alone. Tourist programs were also suspended across the island, it said.

In Mexico the government called a state of emergency and state oil company Pemex launched its hurricane response plan, shutting down production platforms and evacuating personnel, as Dean appeared headed toward its southern Gulf of Mexico oilfields and the refining center of Tampico.

Quintana Roo state Governor Felix Gonzalez ordered the evacuation of the 80,000 tourists from Cancun and other popular barrier islands of the "Mayan Riviera" and blocked the further arrival of more tourists to the area.

"We can evacuate 30,000 tourists by air every day. That gives us enough time to leave hotel occupancy at a minimum, with a reasonable number of guests we can assist and put up in shelters" when the storm strikes, Gonzalez said.

In 2005, Wilma, one of the strongest hurricanes ever, made a direct hit on Cancun and Cozumel and held over the area for hours, wiping out hotels and beaches that have still not been totally rebuilt since.

With Dean currently expected to pass south of the United States, the Houston, Texas-based mission control of the National Aeronautics and Space Administration meanwhile moved to speed up the current space shuttle mission.

It decided to bring the Endeavour shuttle back to Earth on Tuesday instead of Wednesday, in hopes of avoiding a possible forced shutdown of the crucial operations center.