Mother Teresa won the Nobel Peace Prize for her decades of service

Pope John Paul II, unable to pronounce a homily for the first time due to age and illness, presided over the rite which brings the world-famous nun close to sainthood, just six years after her death.

Indian sitar music blended with traditional hymns to celebrate the nun who spent more than 60 years attending to the sick and dying of Calcutta.

Guests included regulars from a soup kitchen in Rome run by Mother Teresa's order and the celebrations extended abroad, to Calcutta itself and Albania in recognition of Mother Teresa's Balkan roots.

BEATIFICATION Beatification requires that a miracle has occurred Group approaches local bishop After Rome's approval an investigation is launched Findings are sent to the Congregation for the Causes of Saints Case is presented to the Pope Blessed may be accorded a feast day Relics of the candidate may be venerated Canonisation (Actual sainthood ) requires proof of a second miracle Profile: Mother Teresa Beatification in pictures

The 83-year-old Pope so admired Mother Teresa that he waived the standard waiting period for beatification to bring forward the honour.

Beatification means that she may now be publicly venerated. For actual sainthood, proof of at least two miracles is required.

"Brothers and sisters, even in our days God inspires new models of sainthood," Pope John Paul told the crowd before his voice failed and aides read out his homily.

"Some impose themselves for their radicalness, like that offered by Mother Teresa of Calcutta, whom today we add to the ranks of the blessed."

Many of Mother Teresa's nuns, standing out from the crowd in their blue-trimmed white saris, wiped away tears, as the crowd cheered.

'Fast track'

Among those attending Sunday's ceremony was Monica Besra, a young Indian woman who claimed in 1998 that her large stomach tumour vanished after praying to Mother Teresa.

The Pope is keen to present modern examples of sainthood

Controversially, the claim was formally recognised as a miracle by the Vatican last year, paving the way for Mother Teresa's beatification.

Before she can officially be made a saint, the Vatican will have formally to attribute a second miracle to her.

The Pope granted a dispensation so the procedure for establishing Mother Teresa's case for sainthood could start just two years after her death.

In normal circumstances five years must pass between the death of the person proposed for beatification and the start of the procedure, to avoid emotion playing a part.

The ceremony in Rome was the second huge gathering in a week in St Peter's Square which was also the scene of the Pope's 25th anniversary celebrations.

During the beatification, 242 faithful needed medical attention, Italy's La Repubblica website reported.

Most of those needing medical attention were senior citizens affected by stress.

Before the beatification began, there were chaotic scenes as more and more pilgrims jostled to find a way into the square, says the BBC's Peter Gould, who was at the ceremony.

Mother Teresa won the Nobel Peace Prize in 1979 for her decades of service to the sick and destitute. She died in 1997, aged 87.

Her Missionaries of Charity order, launched in 1950 with only 12 nuns, has grown to 4,500 sisters in 133 countries. They run homes, schools and hospices for the poor and dying.

Worldwide celebrations

Mother Teresa had her critics, who accused her of mixing with dictators and peddling a hardline Catholicism, says the BBC's Jane Little in Rome.

Mother Teresa's nuns came from around the world to the Vatican

However, the vast crowds outside the Vatican are a testament to her huge popularity that cut across class, nationality and religion, our correspondent adds.

In Calcutta and across India, hundreds of thousands of people watched the beatification ceremony live on television, some of them inmates of leprosy centres or orphanages run by the Missionaries of Charity.

After the ceremony in Rome, some 2,000 homeless men and women who eat and sleep in soup kitchens and shelters run by the order were invited to a special luncheon inside a Vatican hall.