Hurricane Ike barreled toward Cuba as an extremely dangerous Category 4 storm on Sunday and was forecast to sweep into the central Gulf of Mexico as a large and powerful storm echoing Hurricane Gustav.

Ike's top sustained winds reached 135 miles per hour (215 kph), making it an 'extremely dangerous' Category 4 on the five-step Saffir Simpson scale of hurricane intensity, the US National Hurricane Center said.

Forecasters said Ike could strengthen further before sweeping into Cuba late on Sunday, severely threatening sugar cane fields, the tourist hotels of Varadero and the crumbling colonial buildings of Havana.

The densely populated Miami-Fort Lauderdale area in south Florida seemed an increasingly less likely target, but visitors were ordered to flee the vulnerable Florida Keys island chain on Saturday.

Ike was forecast to curve into the Gulf of Mexico in the wake of this week's Hurricane Gustav, plowing toward an area that produces a quarter of domestic US oil. Gustav slammed ashore near New Orleans, which was swamped and traumatized by Hurricane Katrina three years ago but largely spared by Gustav.

Oil companies had begun returning workers to the offshore platforms that were evacuated before Gustav hit Louisiana on Monday west of New Orleans. But one company, Shell Oil Co, said on Saturday it had stopped returning workers in case new evacuations were needed.

The deeper Ike goes into Cuba, the weaker it will be once it re-emerges over the Gulf of Mexico. But over water it was expected to rapidly regain its former intensity.

'In five days there will be a large hurricane in the central Gulf of Mexico,' the hurricane center said. Alerts went up across eastern Cuba as residents shivered at the prospect of another major storm a week after Hurricane Gustav devastated parts of western Cuba.
Tourists were evacuated from the Guardalavaca resort on Holguin province's northern coast, as were thousands of students picking coffee in the mountains.

In Havana, residents lined up at gas stations and searched stores for candles, crackers and canned goods after a forecaster warned on state television that 'almost the entire country is in the danger zone.'    

'It looks like this year we will have no respite,' Eduardo Gonzalez said from eastern Santiago de Cuba, 'and if it continues like this we will have to live out the hurricane season in the shelters.'    

Ike pounded Britain's Turks and Caicos islands on Saturday on a course that would take it through the southern Bahamas and then westward across the length of Cuba. By 11 pm (0300 Sunday GMT) the center of the storm was near Grand Turk Island.

Ike was forecast to batter the islands in its path with storm surge flooding up to 18 feet (5.5 metres) above normal tides. It was also expected to rain new misery on Haiti, where hundreds of people died in flooding and mudslides caused by three earlier storms in the last month.

In the low-lying Florida Keys, visitors were ordered out on Saturday and residents were told to evacuate on Sunday along the lone road linking the island chain to the mainland. - Reuters