(AFP) - Tens of thousands of people paid their respects Monday to former pope Benedict XVI at the Vatican, at the start of three days of lying-in-state at St Peter's Basilica before his funeral.

They began queueing before dawn to view the German theologian's body, which was transferred early Monday from the monastery in the Vatican grounds where he died Saturday aged 95.

"I arrived at 6:00 am, it seemed normal to come and pay homage to him after all he did for the church," said an Italian nun, sister Anna-Maria, near the front of the queue that snaked around the edge of the vast St Peter's Square.

Benedict led the Catholic Church for eight years before becoming the first pope in six centuries to step down in 2013, citing his declining health.

His successor Pope Francis will lead the funeral on Thursday in St Peter's Square before his remains are placed in the tombs beneath the basilica.

He will be buried in the tomb which held pope John Paul II's remains until 2011, Vatican spokesman Matteo Bruni said Monday.

Benedict's body, dressed in red papal mourning robes and a gold-edged mitre, was laid out on a catafalque draped in gold fabric in front of the altar of St Peter's, flanked by two Swiss Guards.

Many of those filing past took pictures on their smartphones, while some prayed or made the sign of the cross.

"The atmosphere is very intimate," Francesca Gabrielli, a pilgrim from Tuscany in central Italy, told AFP inside the basilica.

She said Benedict was "a great pope, profound, unique".

Around 40,000 people had paid their respects by 2:00 pm (1300 GMT), according to the Vatican, citing the police.

- 'Lord, I love you!' -

Benedict died at the Mater Ecclesiae monastery where he had lived for the past decade. His last words in the early hours of Saturday were said by the Vatican to have been "Lord, I love you!"

His body will lie in state for three days, with members of the public allowed in during the day, passing first through the metal detectors used routinely to screen visitors to St Peter's Basilica.

Among the visitors Monday were curious tourists, including Valerie Michalak, on holiday with her family from Benedict's native Germany.

"It's a once in a lifetime chance to be part of this big ceremony," she said.

Thursday's funeral is unprecedented in modern times in that it will be presided over by a sitting pontiff.

Benedict's shock resignation created the extraordinary situation of having two "men in white" -- him and Francis -- at the Vatican.

Papal deaths usually trigger the calling of a conclave of cardinals to elect a successor, but this time Francis remains in post, and will lead proceedings.

The Vatican has yet to release details of the guest list, beyond saying that it will include delegations from Italy and Germany.

Italian Prime Minister Giorgia Meloni, who at the weekend joined world leaders from Joe Biden to Vladimir Putin in paying tribute to Benedict, was among the first to visit his body on Monday morning.

She was greeted by Archbishop Georg Gaenswein, Benedict's long-time aide.

- 'Faithful servant' -

The last papal funeral, of John Paul II in 2005, drew a million faithful and heads of state from around the world.

But Benedict has been an ex-pope for longer than he was pontiff -- and he was a more divisive figure.

A brilliant theologian, he alienated many Catholics with his staunch defence of traditional values and as pope struggled to impose his authority on the church as it battled a string of crises, including over clerical sex abuse.

His successor cuts a very different figure, an Argentine Jesuit who is most at home among his flock and has sought to forge a more compassionate church.

Pope Francis paid tribute to Benedict in three New Year's events at the Vatican over the weekend, "thanking God for the gift of this faithful servant of the Gospel and of the Church".

Francis, 86, has raised the prospect that he might follow Benedict's example and one day resign.

In July, suffering knee problems that have forced him to rely on a wheelchair, he admitted he needed to slow down or think about stepping aside.

Last month, Francis revealed he had signed a resignation letter when he took office should poor health prevent him from carrying out his duties.

© Agence France-Presse