A convoy of 10 buses provisioned with food, water and officers to keep the peace left the District yesterday evening bound for the troubled city of New Orleans, hoping to return by Monday with as many as 400 evacuees who will be sheltered at the D.C. Armory.

Council member David A. Catania (I-At Large), a leader of the effort, said he hoped it would be only the beginning. He called on other communities in the Washington region to take in those in need.

"This is a region of 4 million. We should be able to accommodate more than 400," he said. Catania said that if offers of more shelter space come in, "there's no reason we can't turn those buses right around for more. We have to see."

Mayor Anthony A. Williams (D) echoed Catania's challenge by calling on mayors across the country to open armories, stadiums and gyms to those displaced by Hurricane Katrina.

Williams, who was traveling in New Mexico and unavailable to comment, is president of the National League of Cities.

Salt Lake City, Charlotte and Indianapolis also are working to bring evacuees to their cities, in addition to most cities in the Gulf Coast area that were not struck. Also yesterday, Virginia Gov. Mark R. Warner (D) sent his chief of staff, William Leighty, and an armful of satellite phones to the Louisiana governor's office to help coordinate aid offers that are flowing in from throughout the country.

D.C. officials said their plans for exactly how they will fill the buses are unclear. Because of uncertain road and security situations, D.C. emergency management personnel who will accompany the buses will decide in conjunction with the Federal Emergency Management Agency.

"If it wasn't a chaotic scene, if it was an orderly evacuation, we would be able to give you specifics about what our preferences would be, such as evacuating first the disabled, then the elderly and infants," Catania said. "That would of course be our preference. But the reality on the scene does not permit that. We're going to do the best we can with the resources we have."

D.C. police officers will accompany the buses for security, and each bus will have two drivers so the caravan can drive through the night on its 2,200-mile, round-trip journey.

In addition, a fuel tanker will be in the convoy, ensuring enough fuel without lengthy stops.

City Administrator Robert C. Bobb said the most important thing the convoy can do is cause no harm.

"I've been in enough of these situations where volunteers can become part of the disaster," Bobb said. "That is the last thing we want." He said city emergency management officials have been coordinating with the Red Cross and federal agencies.

"This is not some willy-nilly, do-good, let's-jump-on-buses-and-send-people-to-Louisiana program," Bobb said.

City officials are preparing the armory to accommodate an extended stay by its guests. D.C. public school officials said they will enroll any children who arrive in the bus convoy.

The Washington Nationals, Mystics and D.C. United have offered to organize recreational events and make available some tickets to their games.

D.C. officials also will try to help those who come to the District locate missing relatives and get their affairs in order.

The number of people who will be housed at the armory was set at 400 because that is the number that D.C. National Guard officials said could be accommodated comfortably.

Catania and Bobb said the best way for local residents to help is to donate money to the American Red Cross at 1-800-HELPNOW. Anyone who lives in the District and has room to take in evacuees or who wants to volunteer can call the mayor's citywide call center at 202-727-1000.

Staff writer Michael D. Shear contributed to this report.

Nicholas Brannum, 13, left, Earl Tasco Jr. and Robert Brannum, in truck, organize supplies bound for New Orleans. Volunteers load buses set to leave for New Orleans from the D.C. Armory, where as many as 400 storm survivors will be housed. City officials are calling on other jurisdictions to help house evacuees.