What was billed as an innovative effort to help victims of Hurricane Katrina get back on their feet brought chaos and confusion Thursday as thousands of evacuees jostled for promised federal and private cash assistance.

In Houston and other cities, word spread quickly via radio and television that the Federal Emergency Management Agency would dole out debit cards worth $2,000 starting Thursday -- emergency grants to help increasingly tired and desperate evacuees buy food and gas, and pay mounting hotel bills and other expenses.

At the same time, the American Red Cross launched a similar card program in amounts up to $1,500, depending on family size.

The Red Cross cards were available Thursday, but the FEMA cards, part of a pilot program limited to Houston shelter residents, will not be ready until Friday at the earliest, federal officials said.

Sweltering in 93-degree heat and frustrated by disorganized relief efforts and long lines, people began pushing, shoving and yelling as they jockeyed for position. As a result, police locked down the Astrodome complex at 9 a.m. Many in the crowd did finally get the Red Cross cards.

"We're making up a lot of this as we go," said Joe Leonard, a Coast Guard lieutenant in charge of the Astrodome operation. "It's a dynamic situation. We don't have a playbook for this."

It was the first time FEMA has used debit cards, said Butch Kinerney, an agency spokesman in Washington. Officials said they would monitor how well the program is working and may consider expanding it to other regions as early as next week.

The cards, which bear the MasterCard logo, can be used at ATMs and at any commercial outlet that accepts MasterCard. There are no restrictions on what they can be used for.

"This is a tremendous undertaking to try to get debit cards out with $2,000 on them to thousands of people," Kinerney said. "We've got plenty on hand, and we've got some more on order to make sure that everybody who is in the shelter down there that needs a card gets a card."

The debit cards are part of much broader disaster assistance packages available to storm victims that include small business loans, long-term temporary housing and money for home repairs, funeral costs, medical expenses, transportation and storage and other bills, Kinerney said.

Victims who are staying with relatives and friends, or who are in shelters in other regions, will not be left out, he said. They can get the $2,000 emergency grant right way through electronic direct deposit to their bank accounts or in the form of a FEMA check delivered by mail or hand by the U.S. Postal Service.

In Houston, many would-be recipients stood in anger, confusion and desperation outside the arena's locked south gate.

"They told us to come back at 10 this morning for the card," said Velma James, 56, whose pink plastic wrist bracelet gave her access to the Astrodome complex.

James pointed to her swollen ankles. "I can't stand too long," she said. "I've got hypertension and I'm diabetic. . . . Every night I dream about bodies floating by my house. And now we can't even get in there?"

Inside the gate, mounted police and National Guard soldiers dressed in army fatigues stood guard over a line visible for a half-mile, bulging with children who relief officials said did not need to be present. Many families did not know that.

To qualify for the debit cards and emergency grants, all prospective recipients, even those in shelters, must register with FEMA through the agency's Web site or by calling 800-621-3362. The agency has computers and phone banks available at shelters to enable evacuees to sign up. Hand-written paperwork would not work, Kinerney said, because evacuees' information must be entered into FEMA's computer database before any money can be disbursed.

An applicants' primary residence must have been affected by the storm for the person to qualify for assistance. Applicants must provide FEMA with their Social Security number, information about insurance coverage and gross household income. Grants are limited to $2,000 per household and at least one person in the household must be a U.S. citizen.

Kinerney said officials know that some evacuees may lack documentation; the government will provide them grants anyway.

"We're going to have to take people's words for it and then get back to them later and make sure that they've told us the truth," he said. They will be audited later, and Kinerney said that "if it comes back and we find out that you've defrauded us, then it's a federal crime. We'll file charges against them, absolutely."

Houston police Sgt. David Crane said the stadium entrances were sealed off Thursday. "The issue is people coming off the streets that don't belong in there trying to get benefits," he said. FEMA has been swamped with applications for federal assistance. Eight days after Katrina hit, the agency had received more than 350,000 applications, as opposed to 66,000 after last year's Hurricane Charley in Florida.

But confusion reigned here. From evacuees to relief officials, many were uncertain whether FEMA and the Red Cross were offering the same card.

The Red Cross said it would expand its cards, which are funded by private donations, to other cities in the next few days.

Lee reported from Washington.

Denis Lewis, with her children Marzal and Markell, negotiates the line of hopefuls for a Red Cross debit card.The Red Cross said it would expand its debit card program beyond Houston in the next few days.