By Giselda Vagnoni and Cristiano Corvino

ROME (Reuters) -Tens of thousands of people streamed past the tomb of Pope Francis on Sunday, packing the Roman basilica where he had chosen to be buried in a break from tradition.

No pope had been laid to rest outside the Vatican in more than a century, but Francis opted instead for burial in Santa Maria Maggiore (Saint Mary Major), located in the Italian capital's most multicultural neighbourhood.

His coffin was taken there on Saturday after his funeral Mass in St. Peter's square, with around 150,000 people lining the route through the heart of the city to say their farewells.

The casket was placed in a simple marble tomb in a side aisle of the basilica. Only his name in Latin, "Franciscus", is inscribed on top, while a reproduction of the plain cross that he used to wear around his neck hangs above the niche.

"I feel like it's exactly in the way of the Pope. He was simple, and so is his place now," said Polish pilgrim Maria Brzezinska after paying her respects.

Visitors began queuing well before the Basilica opened at 7:00 a.m. (0500 GMT) and the church rapidly filled with well-wishers after the doors opened. Authorities urged people to leave as soon as they had seen the tomb, saying thousands more were waiting to get in.

Six hours later, 30,000 people had visited St. Mary Major, according to the Vatican.

Tourists leaving the basilica at lunch time said they had been queuing for more than two hours and had only a few minutes inside.

In the afternoon, hundreds of cardinals gathered in the church for prayers.

The church was founded in 432 and is the only basilica in Rome that preserves the early Christian structure, although there have been many later additions.

Francis, who died on April 21 at the age of 88, was especially attached to it because of his devotion to Mary, Mother of God. He prayed there before and after every overseas trip.

A venerated Byzantine icon of Mary is housed in the Pauline chapel near the tomb. A vase of golden roses, donated by Francis in 2023, sits among candlesticks under the icon. He last visited the chapel carrying a bunch of white roses on April 12.

A single white rose was placed on his tomb.

"So much intensity. He was a person close to everyone, so we respect him for what he did, each in our own way. Thank you," said Carmelo Lamurra, a Rome resident.

(Reporting by Giselda Vagnoni and Cristiano Corvino; Editing by Crispian Balmer and Giles Elgood)