Massive explosions rocked the New Orleans riverfront a few miles (kilometers) south of the French Quarter on Friday.
At about 4:35 a.m.(0935GMT) the huge blasts jolted residents awake. The extent of any possible damage was not immediately known.
An initial explosion sent flames of red and orange shooting into the pre-dawn sky. A series of smaller blasts followed, and then acrid, black smoke could be seen even in the dark. The vibrations were felt all the way downtown.
The explosions appeared to originate close to the east bank of the Mississippi River, near a residential area and rail tracks. At least two police boats were at the scene.
Chaos has spread through this desperate city since Hurricane Katrina struck, despite the promise of 1,400 National Guardsmen a day to stop the looting, a $10.5 billion recovery bill in Congress and a relief effort U.S. President George Bush called the biggest in U.S. history.
The hungry beg for help, bodies lie along flooded sidewalks, and bands of armed thugs have thwarted fitful rescue efforts.
Gunfire in some areas on Thursday halted search and rescue efforts.