After pounding Cuba, where it killed at least 10 people, the storm moved into the Gulf of Mexico Saturday, with its center staying well off Key West, a city at the southern tip of a chain of islands linked to mainland Florida by a series of bridges.

But heavy rains and fierce winds on the edge of the hurricane battered the popular tourist destination as well as other parts of southern Florida.

Concern, however, focused on the shores of the Gulf of Mexico, and particularly Alabama and the western Florida Panhandle, where the hurricane was expected to make landfall on Sunday.

Both states were still recovering from the 2004 hurricane damage, particularly Florida, which was hit by four such storms in quick succession last year.

"This is serious. This is a very dangerous storm," said Florida Governor Jeb Bush, a brother of the US president.

"If you are in a mandatory evacuation area, please do so," the governor said at a news conference Saturday.

Over half a million people in the Florida Panhandle and in neighboring Alabama were affected by the evacuation orders.

Oil rigs and platforms in the Gulf of Mexico had already been evacuated in anticipation of the hurricane, which regained strength Saturday after weakening as it crossed central Cuba.

Residents of Key West and the rest of the Florida Keys who did not evacuate ahead of the storm were told to remain indoors, as dangerous weather conditions were expected to continue throughout the day.

Severe storms lashed an area of south Florida reaching from Key West to north of Miami, uprooting trees, downing power lines and leaving about 200,000 people without power.

Authorities warned the storm could also spawn tornadoes and cause serious floods.

Dennis lost strength as it crossed Cuba, but it started regaining steam early Saturday, with sustained winds measuring 160 kilometers (100 miles) per hour. Forecasters expected the storm to strengthen further as it moves over the warm waters of the Gulf of Mexico.

At 9:00 am (1300 GMT) Saturday, the center of Dennis was 175 kilometers (110 miles) west of Key West, the Miami-based National Hurricane Center said.

NASA has decided to go ahead with plans for Wednesday's launch of the Space Shuttle Discovery from Florida's Kennedy Space Center, which lies hundreds of miles (kilometers) north of the hurricane's track.

It will mark the first shuttle launch since the Columbia disaster grounded the flights in February 2003.

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