The return of residents to the stricken city of New Orleans has been suspended amid concerns over Tropical Storm Rita.
Mayor Ray Nagin has told those already back in town to prepare to leave.
His new orders are a sharp reversal of his earlier plan to allow people from neighbourhoods less affected by Katrina to head back to their homes. It is thought that by the weekend Rita could hit Texas, where many of Katrina’s victims have taken refuge.
The mayor says there is also a chance it could hit New Orleans.
He was speaking as the overall death toll from Hurricane Katrina rose to 973.