The latest hurricane to tear through the Atlantic and Caribbean battered Turks and Caicos and the southern Bahamas on Sunday and was hampering relief efforts in flood-devastated Haiti, as Cuba and the United States gird for the storm's wrath.

Hurricane Ike, an "extremely dangerous" Category 4 storm, plowed overnight across the low-lying Turks and Caicos islands, causing some injuries and extensive damage on the British territory and tourist haven, Bahamas Radio reported.

At 1400 GMT on Sunday the storm was raking over the southeastern Bahamian island of Great Inagua, toppling trees, blowing off roofs, causing an island-wide power failure and forcing many of its 1,000 residents to seek refuge in shelters, a resident told AFP.

Bahamas Prime Minister Hubert Ingraham warned residents that Ike "must be taken very seriously" and dispatched Defense Force personnel to Great Inagua to cope with the disaster.

Ike was expected to eventually careen past Florida into the Gulf of Mexico and sweep toward Louisiana and the storm-battered city of New Orleans as early as Tuesday.

A more immediate concern was its effect on Haiti, where a humanitarian crisis was unfolding after flooding from previous Hurricane Hanna left more than 500 people dead and thousands in desperate need of food, clean water and shelter.

With winds near 215 kilometers per hour, Ike was to churn just north of Haiti on its way to Cuba, but further flooding in Haiti is expected as the storm's outer rain bands were to unleash downpours on the country's vulnerable northwest coast.

"These rains could cause life-threatening flash floods and mudslides over mountainous terrain," the center warned, predicting "some strengthening" of the storm.

It was an ominous forecast for the poorest country in the Americas, already reeling from the destruction inflicted by three storms in as many weeks, and where the United Nations has warned the death toll from Hanna's floods was "increasing hourly."

Praying for peace

The disaster prompted prayers from Pope Benedict XVI. "I want to remember the dear population of Haiti, greatly distressed in recent days by passing hurricanes," Benedict told pilgrims on the Italian island of Sardinia.

Some 650,000 Haitians have been affected by the flooding, including 300,000 children, and the task of delivering crucial aid has been complicated by dismal transport conditions, according to UNICEF.

A chilling scene has emerged in the northwestern Haitian town of Gonaives, a flood-prone coast city of some 350,000 where hundreds of bodies were found after a five-meter wall of water and mud engulfed much of the town, the United Nations has said.

Senator Yuri Latortue, who represents Gonaives, said 200,000 people have been without food and clean water, many for four days. Rivers were muddy brown as they spilled over into entire villages, many of which remained Sunday under half a meter of water.

Blue-helmeted UN peacekeepers on Saturday evacuated several thousand residents from Gonaives, a civil protection official there said, but thousands more awaited relief.

"The water has only started to recede. We've finally managed to reach the people of Gonaives," said Jean-Pierre Taschereau, a Haitian Red Cross coordinator. "This new hurricane alert is a very bad one. Rain risks complicating the situation even more," he said, warning there could be food shortages.

After clipping Haiti, Ike was on course late on Sunday to plow westward into northeastern Cuba.

Cuba - where Hurricane Gustav damaged or destroyed 140,000 homes a week ago - was on high alert. "Almost our entire country is in the danger zone," Jose Rubiera, the head of Cuba's Insmet weather agency, told Cuban television.

Some 250,000 Cubans began evacuations Sunday ahead of Ike's impending landfall, local officials said.

Meanwhile, in the southern US state of Florida, officials and residents also got ready for Ike's arrival. Densely populated south Florida, including the cities of Miami and Fort Lauderdale, has not been hit by a major hurricane since Hurricane Andrew in 1992.

The center of Ike was forecast to rake over the Florida Keys, where a phased evacuation has begun for the string of islands.

"We've learned from the past. They're so fickle," Rob Mitchell, owner of Keys Divers snorkeling outfit in Key Largo, said of the hurricanes that lash Florida. "It can be aiming right away from you, and all of a sudden turn."