Thousands of residents are fleeing the southern U.S. city of New Orleans, as powerful Hurricane Gustav approaches from the Gulf of Mexico.

U.S. forecasters say Gustav may enter the northern Gulf of Mexico by Monday morning.  They have warned that the dangerous storm could make landfall early Tuesday near the city, which was devastated by the effects of Hurricane Katrina three years ago.

New Orleans officials say 3,000 residents have voluntarily been evacuated on buses and another 17,000 are waiting to be transported out. Thousands of other people are fleeing by car, clogging roadways headed out of the city.  City leaders say mandatory evacuations may be ordered as early as Sunday morning.  

In 2005, Hurricane Katrina struck New Orleans, killing hundreds of people and causing more than $100 billion in damage.

State and federal officials were accused of failing to properly respond to the catastrophe, and leaving many residents to die.

The White House says President George Bush is keeping in touch with state and federal officials, to ensure that the region is prepared to respond if Gustav should strike the southern United States, as predicted.

Some information for this report was provided by AFP, AP and Reuters.