WASHINGTON (By David Stout, NYTimes) September 9, 2005 - Michael D. Brown, the embattled head of the Federal Emergency Management Agency, today was relieved of his duties overseeing recovery efforts in the Gulf Coast region.

The secretary of homeland security, Michael Chertoff, described Mr. Brown's reassignment to FEMA headquarters here as a logical step in keeping with Mr. Brown's overall duties as FEMA director. Mr. Chertoff, speaking in Baton Rouge, La., said in a televised news briefing that the hurricane-recovery mission would now be led by Vice Adm. Thad W. Allen, the third-ranking officer in the Coast Guard.

"Michael Brown has done everything he possibly could to coordinate the federal response to this unprecedented challenge," Mr. Chertoff said, accompanied by Admiral Allen and Mr. Brown. "I appreciate his work, as does everybody here."

Those words did not reflect the fierce criticism that Mr. Brown has come under for the federal government's response to Hurricane Katrina and the disastrous flooding that followed, particularly in New Orleans. Some Congressional Democrats have demanded that President Bush fire him outright, and they criticized Mr. Brown anew this afternoon, after the announcement that he was being reassigned.

"At last President Bush has recognized what I have been saying for more than a week," the House minority leader, Nancy Pelosi, Democrat of California, said shortly after Mr. Chertoff's announcement. "The federal response to this disaster must be managed by a capable leader."

But Senator Harry Reid of Nevada, the Senate minority leader, and three of his party colleagues demanded that Mr. Brown be sacked altogether.

"It is not enough to remove Mr. Brown from the disaster scene," they said in a letter to President Bush. "The individual in charge of FEMA must inspire confidence and be able to coordinate hundreds of federal, state and local resources. Mr. Brown simply doesn't have the ability or the experience to oversee a coordinated federal response of this magnitude."

In addition to Mr. Reid, the letter was signed by Senators Richard Durbin of Illinois, the minority whip, and Debbie Stabenow and Charles E. Schumer of New York.

Admiral Allen is the Coast Guard chief of staff. On Monday, he was dispatched to the gulf region as Mr. Brown's deputy in the recovery efforts. The admiral's official biography describes him as "a specialist in operations both in coastal and offshore environments."

Before becoming chief of staff in May 2002, he headed the Coast Guard's Atlantic operations and was in charge of 26,000 military and civilian employees in an area covering 14 million square miles.

A week ago today, Mr. Brown was at President Bush's side as the president made his first visit to see the devastation caused by the storm. "Brownie, you're doing a heck of a job," Mr. Bush said then.

But today, the chief White House spokesman, Scott McClellan, declined repeated opportunities to say that Mr. Brown still enjoyed the president's full confidence. "We appreciate all those who are working around the clock, and that's the way I would answer it," Mr. McClellan said.

With each passing day since the storm pounded the Gulf Coast, the criticism of Mr. Brown, a lawyer whose credentials indicated no emergency-response experience when he became head of FEMA two years ago, has only increased.

Several days into the crisis, Mr. Brown acknowledged in an interview with Paula Zahn of CNN that he was not aware that thousands of New Orleans residents were huddled in the city's convention center under increasingly dire circumstances.

As recently as Thursday there was obvious disarray within FEMA, as agency spokesmen in Baton Rouge and Washington gave conflicting answers on whether the agency would proceed with plans to use debit cards to distribute financial aid to people dislocated by the storm.

Mr. Brown's standing was further clouded when Time magazine reported on its Web site Thursday that he had embellished some of his credentials. When he was asked today whether he had done so, and whether he would resign from FEMA, Mr. Brown was silent.

Instead, Mr. Chertoff spoke up. "You heard the ground rules," he said. "I'm going to answer the questions." Earlier, Mr. Chertoff had advised reporters to choose their questions carefully, because his time was limited.

Mr. Brown, when asked by The A.P. whether he thought he was being made a scapegoat, replied: "By the press, yes. By the president, no." Mr. Brown said in a telephone interview that he was "anxious to get back to D.C. to correct all the inaccuracies and lies that are being said."

Nor was Mr. Brown without his defenders today. One of them was Carl Reherman, a former councilman and later mayor of Edmond, Okla., who said Mr. Brown was involved in setting up an emergency operations center there in the 1970's. "He not only worked very hard on everything he did, he had very high standards," Mr. Reherman said in an interview with The A.P.