FATIMA, Portugal - Around 200,000 pilgrims flooded the shrine of Fatima in Portugal on Saturday to attend a service held by Pope Francis at one of Catholicism's most revered sites devoted to the Virgin Mary.

Worshippers waved and called out "Viva!" as the 86-year-old pontiff, wearing a white cassock, slowly drove past on his popemobile.

He paused several times to have babies brought to him and kissed them on the head.

The pope then recited the rosary with 112 sick youths, people with disabilities and prisoners at the chapel built on the spot where the Virgin Mary is said to have appeared to three shepherd children in 1917, and delivered a speech.

In an address to the crowd estimated by local authorities at around 200,000 people, he reinforced calls made many times during his trip to Portugal for an inclusive Church.

"This little chapel where we find ourselves, is like a beautiful image of the Church, welcoming, without doors," he said in improvised remarks.

"The Church does not have doors, so that everyone can enter," he added to applause from the crowd.

It is the second day in a row that the pope, who is in increasingly fragile health and now uses a wheelchair or walking stick to get around, has not followed his prepared remarks.

A Vatican spokesman told AFP that the pope had improvised one of his speeches on Friday due to "discomfort of vision", but that in Fatima it had been "a choice".

- 'Peace and tolerance' -

Francis arrived in Portugal on Wednesday for World Youth Day, a six-day international Catholic jamboree.

After the service in Fatima, about 150 kilometres (90 miles) north of Lisbon, he returned by helicopter to the capital, where on Saturday evening he will lead a vigil at the waterfront Parque Tejo.

Church organisers expect one million faithful will attend the vigil at the park that has been built for the occasion on a former landfill site.

Fatima draws millions of pilgrims from around the globe.

Many pilgrims walk to the town and some complete the final stretch on their knees to demonstrate their devotion.

Others toss wax limbs or organs into a fire beside the chapel as they recite prayers for healing.

Thousands of worshippers had already gathered in Fatima on Friday on the eve of the pope's arrival, many setting up folding chairs in the shrine's vast square to mark their spot.

Many slept in sleeping bags or floor mats on the esplanade of the shrine.

"It is important to be here to see this pope who inspires peace and tolerance," said Marta Noronha, a 36-year-old doctor who came to Fatima with her parents and her brother.

- 'Last chance' -

The shrine contains dozens of shops where souvenirs are sold alongside rosaries, bibles and assorted images of the Virgin Mary.

Susana Marino, a 48-year-old Portuguese psychologist, said she had come to Fatima because "it really will be the last chance we have to see the pope".

"To see all these people now is wonderful. The pope manages to mobilise the crowds and it's really showing here."

Francis will deliver a mass on Sunday on the last day of his visit at the Parque Tejo when a heatwave is expected to peak, with temperatures forecast to soar to 41 degrees Celsius (105.8 degrees Fahrenheit).

Local authorities have repeatedly urged pilgrims to drink plenty of water.

Registered participants received rucksacks containing reusable water bottles and sunhats, along with a rosary.

World Youth Day, created in 1986 by John Paul II, is the largest Catholic gathering in the world and will feature a wide range of events, including concerts and prayer sessions.

This edition, initially scheduled for August 2022 but postponed because of the pandemic, will be the fourth for Francis after Rio de Janeiro in 2013, Krakow in 2016 and Panama in 2019.