Nagin has said the city will remove all residents. He has not provided details on how or when the process would be carried out. But Riley warned Monday that officials were considering "stopping food drops" to the stragglers to increase the pressure on them to leave.
There were emerging signs that water-borne bacterial disease has begun to fester among survivors being brought out of the flood zone by military and police search teams. Medical authorities working in the city report treating several cases of vibrio vulnificus, a gastrointestinal disease that spreads through exposure to polluted water.
Health officials said they clearly identified strains of the disease, which has effects similar to cholera, among some storm refugees. But they do not yet have a handle on the number of cases.
"We are seeing some cases," said Von Roebuck, a spokesman for the Centers for Disease Control and Prevention in Atlanta. "It could be life-threatening."
For The Record
Los Angeles Times Wednesday September 07, 2005 Home Edition Main News Part A Page 2 National Desk 1 inches; 44 words Type of Material: Correction
New Orleans street -- A photo caption on the front page of Tuesday's Section A with coverage of Hurricane Katrina said a rescue boat was on Elysian Fields Avenue. The street was near Elysian Fields, but the rescue team was not on that thoroughfare.
Among healthy people, the illness can cause vomiting, diarrhea and abdominal pain but is generally not life-threatening. It can be cured with antibiotics. But it can be more serious among people with chronic liver disease and compromised immune systems, leading to fever, chills and septic shock.
"The water quality in the streets continues to deteriorate," said Nagin, who said he was concerned about West Nile virus and other mosquito-borne diseases. "There is some really nasty looking stuff out there."
In a visit to the Louisiana Emergency Operations Center in Baton Rouge, Bush told several hundred local, state and federal public safety officials that their efforts in evacuating and providing medical treatment and food to tens of thousands of flood survivors brought "immediate light to people who needed help."
Bush returned to the storm-torn Gulf Coast region for the second time in three days to boost the morale of authorities and urge churches and other religious organizations to aid the flood victims of Louisiana, Mississippi and Alabama.
"I want to thank every church member who's helping people who have been displaced," Bush said as he toured the Bethany New World Prayer Center in Baton Rouge, consoling refugees along with televangelist T.D. Jakes and Louisiana Gov. Kathleen Babineaux Blanco.
Behind the scenes there were tensions between Blanco and the administration over the White House's attempt last week to force her to cede the constitutional authority she wields over the Louisiana National Guard.
A senior administration official who spoke on condition of anonymity confirmed Monday that top White House officials had pressed her to allow federal officials to unify National Guard and active-duty troops under one chain of command. The official said that "we wanted to unify the command and control for security" under Army Lt. Gen. Russel L. Honore, who is heading National Guard troops in New Orleans.
But Blanco has resisted, fearing the White House is attempting to paint her as the weak link in last week's slow-moving government disaster operations. On Monday, Blanco's aides learned only at the last minute that Bush was touring the state capital in Baton Rouge and complained that she was being punished for holding tight to her constitutional authority over state-based National Guard units.
When the two sat together at the Emergency Operations Center, Bush smiled benignly while Blanco stared ahead solemnly. At one point, Bush leaned over to give her a peck on the cheek, but her stern gaze did not waver.
Later, Blanco minimized rumors of sniping and said she supported the work of the Federal Emergency Management Agency, which has drawn sharp criticism in recent days. "This debate was simply about an organizational structure," she said. "We needed the versatility to use the National Guard members as they needed them."
After attending a meeting with Bush, Blanco and other federal and state officials, James Lee Witt, the former Clinton administration FEMA director, said that "in two days, you'll see a different program down here."
But Witt, who was hired as an advisor last week by Blanco to shore up her emergency planning and to blunt federal efforts to seize authority over military relief operations, also said that the Bush administration had "minimized FEMA" by folding it into the Department of Homeland Security.
"You can't report up through three different chains of people and make things go fast," Witt said. "FEMA needs to be put back as an independent agency with the people and resources to do its job well."
Homeland Security Director Michael Chertoff and FEMA head Michael D. Brown have been under fire for moving aid in too slowly and for not coordinating with local officials. They continued to defend their performance.
During one news conference Monday, a perturbed Brown resorted to listing his previous experience dealing with public emergencies.
"Yeah, I've been through a few disasters in my life," he said.