Pope Francis was to travel Wednesday to the heartland of the Mapuche, Chile's largest indigenous group, which complains of discrimination and abuse and is seeking the return of ancestral lands now in private hands.

The visiting Pontiff will pay a short visit to the city of Temuco, 800 kilometers (500 miles) south of the capital Santiago, to make direct contact with Mapuche leaders after presiding over a huge open air mass.

Francis will then return to Santiago to meet young Chileans and visit a Catholic university.

His three-day visit has been met with protests by Chileans over clergy sex scandals, with six churches set alight in Santiago.

That anger has spread to the Mapuche homeland known as Araucania, where two small churches were also set on fire amid tension over the group's land claims.

Centuries ago the Mapuche controlled vast swathes of Chile. But today, accounting for seven percent of the population, they hold only five percent of their ancestral lands.

On Tuesday the pope conferred alone with a small group of victims of sexual abuse by priests in Chile, after he publicly asked for forgiveness and riot police broke up a protest near the first public mass of his South American visit.

During the "strictly private" meeting at the Vatican's Apostolic Nunciature embassy in Santiago, the victims "spoke of their suffering to Pope Francis, who listened to them and prayed and cried with them," the Vatican said.

Earlier, the 81-year-old pontiff said: "I cannot begin to express the pain and shame that I feel over the irreparable harm caused to children by some ministers of the church," vowing to commit to ensure the abuses would never happen again.

Francis made those comments during a visit to President Michelle Bachelet's official Moneda Palace residence, drawing applause from pilgrims watching on giant screens in a Santiago park where he later celebrated an open-air mass for some 400,000 people.

But the pope did not receive a universal welcome, with scuffles breaking out between riot police and demonstrators near O'Higgins Park.

Police used armored vehicles to fire water cannons at the demonstrators, bundling some of them into vans. More than fifty people were arrested, authorities said.

- 'Pedophile accomplices' -

Many of the demonstrators chanted "pedophile accomplices" as they approached the park.

A man dressed as the pope and two other people dressed as nuns unfurled a banner from the balcony of a nearby building that read: "Francis, accomplice of pedophile crimes."

Under the 1973-1990 Augusto Pinochet military dictatorship, the church was admired for its human rights advocacy role. But today, Chile is the Latin American country most critical of the Vatican.

Francis's visit -- his first to Chile as pope -- has been overshadowed by a report outlining the depth of sexual abuse in the local church, and his appointment of a bishop who many here believe covered up the country's most prominent sex abuse scandal.

The US-based NGO Bishop Accountability said ahead of the visit that almost 80 Roman Catholic clergy members had been accused of sexually abusing children in Chile since 2000.

For some victims, the pope's request for forgiveness did not go far enough.

"We need concrete actions that the pope has not taken with the Chilean church," said Juan Carlos Claret, spokesman for a lay association in the southern city of Osorno.

Claret's group is demanding Francis remove Osorno bishop Juan Barros, whom he appointed in 2015, despite Barros's ties to a disgraced pedophile priest Fernando Karadima.

In a first for Francis, he visited a women's prison, telling inmates at Santiago's San Joaquin Female Penitentiary that "losing our freedom does not did not mean losing our dreams and hopes."

About 100 inmates welcomed him with songs and excited applause, some of them with their small children.

Source: AFP