The Governor of Louisiana, Kathleen Blanco, has declared a state of emergency in western Louisiana and urged people to evacuate as Hurricane Rita headed toward the Gulf of Mexico.
The Mayor of New Orleans, Ray Nagin, has said that evacuations of the city, already ravaged by Hurricane Katrina, had now begun again.
His comments come as Hurricane Rita has lashed the low-lying islands of the Florida Keys with squalls.
Rita grew from a tropical storm to a hurricane with 160 km/h winds in a matter of hours as it battered the fragile keys and was expected to strengthen further as it moved into the Gulf of Mexico.
The storm was forecast to head west toward the Texas coastline, raising fears it could bring more rain to an already flooded New Orleans and threaten the recovery of oil production facilities damaged by the earlier hurricane.
All 80,000 residents had been ordered out of the island chain and the Governor of Florida, Jeb Bush, has declared a state of emergency.
However, many of the keys' residents stayed behind in boarded-up homes.
