Pope Benedict XVI has told Australians he is deeply sorry for the sexual abuse of children by some Catholic priests.
Speaking at a gathering of bishops in Sydney, the Pope spoke of the "shame we have all felt" and called for abusers to face justice.
A campaign group criticised the speech, saying the Pope should have met some victims to apologise in person.
The Pope was speaking as thousands of Catholic pilgrims began gathering for a candlelit prayer vigil in Sydney.
The pontiff will lead the vigil at the city's Royal Randwick Racecourse.
The Pope is in Australia to mark World Youth Day, which is drawing Catholics from around the world to the country.
Speaking earlier at St Mary's Cathedral in Sydney, he said: "I am deeply sorry for the pain and suffering the victims have endured.
Pope Benedict XVI gives a mass in Sydney
"These misdeeds, which constitute so grave a betrayal of trust, deserve unequivocal condemnation.
"Those responsible for these evils must be brought to justice," the Pope said.
Former victim John McNally said he accepted the apology - although the abuse had long-lasting effects.
"It didn't just happen 40 years ago, as in my case," he said.
"I re-live it day-after-day, and victims re-live their trauma day-after-day. They need constant care with dignity, and the Church has never provided care with dignity."
Victims want action, not just words
Anthony Foster, the father of two Australian girls who were raped by a Catholic priest, said: "He [the Pope] didn't settle the issue we're very concerned about - the issue of him taking direct responsibility to ensure that all the archdioceses provide practical unlimited help to the victims of the Catholic Church."
Daniel Bidinger, a 25-year-old German pilgrim in Sydney, said the Pope's apology was " a good gesture".
"The church should be open about it and shouldn't cover up these incidents," he told the AP.
Broken Rites, which had wanted the Pope to meet some of the victims in person, said the pontiff's apology "is not enough".
"Victims want action, not just words," the group said in a statement.
Broken Rites says there have been 107 convictions against Catholic clergymen on sex charges in Australia. But the campaigners estimate the number of victims to be in the thousands.
There was no immediate confirmation of whether the Pope would meet abuse victims - as he did during a US trip in April, when he also expressed shame for the scandal.
The BBC's Nick Bryant, in Sydney, says victims have complained that the Church in Australia has tried to stall compensation claims and cover up certain cases.
On Saturday, several hundred protesters rallied in Sydney against the Pope's opposition to homosexuality and contraception.
Police said there were minor scuffles as some of the demonstrators pelted Catholic pilgrims with condoms.
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