LONDON— The body of Diana, Princess of Wales, was brought back to Britain on Sunday by Prince Charles, and Prime Minister Tony Blair expressed a nation's grief over the loss of "the people's princess" after her storybook life ended tragically when a car she was riding in crashed at very high speed in a Paris tunnel.

The death provoked an outpouring of emotion here and around the world that underscored Diana's claim to the self-styled title "queen of peoples' hearts," a role she sought to carve out for herself through charity work over many years and intensified after her divorce a year ago from Charles, the heir to the British throne.

Thousands of people, many in tears, gathered outside Diana's Kensington Palace home here and at nearby Buckingham Palace, leaving mountains of flowers, while world figures from President Bill Clinton to Mother Theresa paid tribute to her compassion and humanitarian work, most recently on behalf of efforts to ban land mines.

"I feel like everyone else in this country today, utterly devastated," Mr. Blair said before entering church services in his Sedgefield constituency. "She was the people's princess, and that's how she will stay, how she will remain, in our hearts and in our memories forever." President Nelson Mandela, who played host to Diana on her recent visit to South Africa, remembered her as "undoubtedly one of the best ambassadors of Great Britain."

President Jacques Chirac accorded Diana full military honors from the Republican Guard at the Paris hospital where she died, and then accompanied Charles to a military airport outside Paris on Sunday evening.

"She was a young woman of our time, warm, full of life and generosity," Mr. Chirac said. Diana's body arrived at the Royal Air Force base in Northolt, where it was met by Mr. Blair and an air force honor guard. The body was taken by hearse to a private London mortuary.

The accident occurred very early Sunday as Diana and her companion, Dodi al Fayed, who was also killed along with the driver, were seeking to elude or outrun a pack of photographers on motorcycles.

The tragedy unleashed a wave of criticism of Britain's press and the armies of paparazzi who supply the newspapers and celebrity magazines around the world with pictures. Their attention over the past 17 years made Diana arguably the most photographed and recognizable person in the world, but in the end they appeared to literally hound her to her death.

Diana's brother, Earl Charles Spencer, spoke bitterly from his home in Cape Town, South Africa. "It would appear that every proprietor and editor of every publication that has paid for intrusive and exploitative photographs of her, encouraging greedy and ruthless individuals to risk everything in pursuit of Diana's image, has blood on his hands today," he said.

Foreign Secretary Robin Cook, who spoke during a visit to the Philippines, said that "serious questions will need to be asked if the aggressive intrusion into her privacy has contributed to this tragedy." Other politicians were more hesitant, however, noting that the previous Conservative government had failed in its attempt to draft a privacy law and that Diana had died in France, whose tough privacy laws did little to protect her.

Diana and Mr. al Fayed were returning to Mr. al Fayed's Paris apartment after dining at the Fayed-owned Ritz Hotel when their car, a chauffeured Mercedes, crashed into the wall of a tunnel under the Place d'Alma, along the Seine in central Paris, while trying to elude photographers. They were traveling, according to witnesses, at very high speed and it is not known exactly what caused the car to hit the side of the tunnel.

Diana, 36, died at the Pitie-Salpetriere hospital in Paris around 4 A.M. Sunday morning after doctors labored for more than two hours to try to stem bleeding from her massive injuries. Mr. al Fayed and the driver were declared dead at the scene. Trevor Rees-Jones, Diana's bodyguard, was expected to recover from his injuries, doctors said.

Mohamed al Fayed, the Egyptian-born businessman, Harrods's owner and father of Dodi, decried the deaths as "appalling and quite needless." Mr. al Fayed said, "The world has lost a princess who is simply irreplaceable."

The royal family was on its traditional summer vacation in Balmoral, Scotland, when news of her death arrived. Charles woke their two children, William, aged 15, and Harry, 12, to break the news.

It was not immediately clear what funeral arrangements would be, but government officials indicated there would not be a state funeral since Diana was no longer a member of the royal family.

It was a tragic and ironic end to a life that has transfixed Britain and much of the world since Diana Spencer burst onto the scene 17 years ago.

The product of a broken family with close ties to the House of Windsor, Diana, then 19, was working as a kindergarten teacher in London when she became engaged to Charles, 12 years her senior. Their 1981 wedding was an extravagant display of royal pageantry that uplifted a recession-bound nation.

But the couple's differences in expectations and attitudes quickly became apparent. Diana spoke in a 1995 television interview about her depression, her struggle with the eating disorder bulimia, and several attempts at suicide.

According to her own words and those of close acquaintances, Diana had begun to find some of the happiness she lacked in marriage with Dodi al Fayed. Their sudden romance in the past two months had been the story of the summer here.

A photograph of the couple kissing while vacationing at Mr. al Fayed's home in the south of France in recent weeks reportedly sold for $200,000, a figure that explains the behavior of photographers. Steve Coz, editor of the National Enquirer, said on television that photographs of the crash scene were being shopped around for $1 million but that the American tabloid had turned the offer down.

President Bill Clinton, who interrupted his vacation on Martha's Vineyard to express condolences, said he and his wife, Hillary, "liked her very much."

"We admired her work for children, for people with AIDS, for the cause of ending the scourge of land mines in the world, and for the love of her children, William and Harry," he

said.