Tropical Storm Gustav churned toward Cuba and the United States Wednesday after lashing Haiti and the Dominican Republic with hurricane force winds and rain that killed 22 people.

The US National Hurricane Center warned that Gustav could regain hurricane force on Thursday as it passes between Jamaica and the southeastern coast of Cuba, pushing oil prices higher on fears that the storm could strike rigs in the Gulf of Mexico.

"Slow strengthening is forecast once Gustav moves away from Haiti, and the storm could regain hurricane strength within the next day or two," the NHC said.

The Cuban Meteorological Institute said Gustav could strengthen to a Category two or three hurricane on the five-level Saffir-Simpson scale. It made landfall in Haiti Tuesday as a Category One hurricane, the lowest level.

A hurricane alert Wednesday covered Cuba's eastern provinces of Guantanamo, Santiago and Granma, and some 50,000 people were evacuated from zones at risk.

The center of the storm was situated at 1800 GMT at 90 miles (145 km) southeast of Guantanamo, Cuba, the NHC said.

The US Department of Homeland Security meanwhile urged Gulf Coast residents to get ready for the storm, with the city of New Orleans, Louisiana in its possible path almost exactly three years after the area was devastated by Hurricane Katrina.

A five-day forecast by the NHC said Gustav could smack the US Gulf Coast, with its eye aimed at New Orleans, on Monday.

"Regardless of its predicted path, it is important for citizens in the Gulf Coast region to listen to what their local officials are advising over the course of the next few days and to take these simple steps to prepare," said Homeland Security Secretary Michael Chertoff.

"If residents make individual and family preparations, they make it easier for first responders to focus on people who can't help themselves and need help first."

Louisiana's Governor Bobby Jindal activated a storm crisis team and vowed to lead advance preparation efforts.

"As long as there is a chance that we'll be in this storm, I'll be here in Louisiana," said Jindal, warning he may miss next week's Republican National Convention to nominate John McCain as the party's candidate for the White House.

"I'm going to make sure I'm here personally to lead the preparation efforts and if necessary, any recovery efforts necessary after the fact," he told CNN.

The storm was blowing winds of 60 miles per hour (95 kilometers) as it stalled over Haiti about 140 miles (225 km) west of Port-au-Prince, the US center said in its latest report.

At least 14 people died and seven were injured in Haiti, mainly the southeast, as roofs flew off houses and electricity pylons were ripped away by violent winds, authorities said.

In the Dominican Republic, which shares the island of Hispaniola with Haiti, eight people were killed in a mudslide caused by the storm.

All the victims were members of the same family, and had just returned to their home after evacuating two weeks ago, believing it safe after Tropical Storm Fay earlier this month, officials said.

Fay pummeled the Caribbean and left at least 47 people dead or missing, most of them in Haiti. The storm killed 11 more people in Florida.

Gustav was expected to drop six to 12 inches of rain over the Dominican Republic and Haiti, the NHC said, warning that the rains were likely to "produce life threatening flash floods and mud slides."

World oil prices shot up on the New York market Wednesday after energy giant Royal Dutch Shell said it had begun "evacuating personnel not essential to producing and drilling operations in the Gulf."

New York's main contract, light sweet crude for delivery in October, advanced 1.88 dollars to close at 118.15 dollars a barrel.

In London, Brent North Sea crude for October rose 1.59 dollars to settle at 116.22 dollars.