'Desperate SOS' for New Orleans

New Orleans' mayor issued an urgent plea for relief of his flooded city yesterday as gunshots and looting hampered the evacuation of desperate crowds trying to escape Hurricane Katrina's destruction.

"This is a desperate SOS," Mayor Ray Nagin said in a statement read by CNN. Some of the thousands of hungry, thirsty storm survivors outside the city's convention center chanted similar pleas.

"Right now we are out of resources at the convention center and don't anticipate enough buses. Currently the convention centre is unsanitary and unsafe and we are running out of supplies for 15,000 to 25,000 people," Mr Nagin said.

Shell-shocked New Orleans officials tried to clamp down on looting in the historic jazz city reduced to a swampy ruin by Monday's storm. Bodies floated in the streets, attackers armed with axes stripped hospitals of medicine and authorities said they could still only guess at how many people had died.

Federal disaster declarations covered 234,000 square kilometres along the US Gulf Coast, an area roughly the size of Great Britain. As many as 400,000 people had been forced to leave their homes.

Violence broke out in pockets of New Orleans among the wandering crowds desperate to escape the flooded city and hellish 32°C. "We want help," people chanted outside the convention centre."

Boat rescues were delayed because of the danger and police rescuers shifted their focus to fighting looting and other crime that gripped the city.

A National Guard official said as many as 60,000 people had gathered at the increasingly squalid Superdome stadium for evacuation. But the operation was suspended after reports that someone fired at a military helicopter sent to ferry out survivors. A National Guard soldier was shot and wounded in the arena on Wednesday.

Nearly 5,000 National Guard troops were mobilised in Louisiana. The military said the number would rise to 21,000 by today and 30,000 in the next few days, mostly in Louisiana and Mississippi but also in storm-stricken parts of Alabama and Florida.

Power and water were off and supplies were exhausted. Critically ill patients were dying one by one without oxygen, insulin and intravenous fluids, the pilot said.

Looting and tension eased in Biloxi, Mississippi, as troops arrived and the Salvation Army began serving 1,200 meals a day at a canteen set up beside the charity's demolished building.

Some of those left hungry and homeless after Katrina shattered the Mississippi coast with a nine-metre wall of water volunteered to help serve, and food lines were orderly.

Search crews probed the rubble of collapsed buildings with heat-sensing robots in search of the living and cadaver dogs to find the dead. They were still pulling out survivors, and leaving behind corpses trapped under debris.

US President George W. Bush condemned the looting and warned against charging artificially high prices for gasoline.