Officials are trying to pin down the source of a deadly amoeba found in the water supply of a suburban New Orleans community.

The pace of rebuilding after Hurricane Katrina has slowed, leaving some Gulf Coast areas with less than half the people they had before the storm.

Hurricane Rita ploughed into the Gulf Coast early today, lashing Texas and Louisiana with driving rain, threatening to flood low-lying regions and knocking power out to half a million people as transformers exploded in the pre-dawn sky.

OUTER bands of rain from Hurricane Rita began falling in New Orleans yesterday and forecasts of between eight and 13 centimetres of rainfall in the coming days raised fears the patched levee system could fail and flood the city all over again.

Police in New Orleans supported by troops have begun to use force to remove people from their homes in the city.