The Pope has said he made "serious mistakes" over a case of alleged child abuse by Catholic clergy in Chile.

In a letter to the South American country's bishops, Francis said he felt "sadness and shame" over comments earlier this year in which he accused the victims of committing slander.

The letter, released by the Church in Chile, said the Pope would invite some of the victims to Rome.

A Chilean bishop, Juan Barros, is accused of hiding abuses by a priest.

Pope Francis made his controversial remarks during a visit to Chile in January.

Defending Bishop Barros, he said: "There is not a single piece of proof against him. Everything is slander."

Bishop Barros has not been accused of abuse, but of being present when another priest, Fernando Karadima, molested young boys in Santiago, starting in the 1980s.

Father Karadima never faced prosecution as too much time had passed, but the judge who heard victims' testimony described them as "truthful and reliable".

The Pope's comments in January prompted an angry response from some of the victims. They told reporters that the Pope's demand that they provide evidence was "offensive and unacceptable".

At the end of his Latin American trip, the Pope apologised by saying he realised his words had hurt many. But he reiterated his belief that Bishop Barros was innocent.

In the letter released by the Chilean Church on Wednesday, the Pope says he "made serious mistakes in assessing and perceiving the situation, especially due to a lack of truthful and balanced information".

He said he hoped he could apologise personally to the victims, and invited them to come to the Vatican over the next few weeks.

After his trip, Pope Francis sent Maltese Archbishop Charles Scicluna to investigate allegations of a Church cover-up of the abuse in Chile.