LONDON — Pope Benedict XVI has met with victims of priestly sexual abuse and prayed with them even as abuse survivors and thousands of people opposed to his visit marched in central London in the biggest protest of his five-year papacy. Bill Kilgallon, chairman of the National Catholic Safeguarding Commission — a church group that organized the encounter — said five people met with the pontiff for about 30 or 40 minutes Saturday. Vatican spokesman Rev. Federico Lombardi said the pontiff was "moved by what they had to say and expressed his deep sorrow and shame." During a Mass in Westminster Cathedral, Benedict said he hoped the church's humiliation would help victims heal and help the church purify itself and renew its commitment to educating the young. His comments, which were in line with his previous statements on the topic, were directed at Britain's Catholic community in the seat of the English church, a sign that Benedict wanted to speak to the faithful about the humiliation they all felt as Catholics. Hours later, abuse victims and demonstrators opposed to the pope's stance against homosexuality, abortion and using condoms to fight AIDS marched from Hyde Park to Downing Street to protest the pope's four-day state visit. They carried banners reading: "The pope is wrong — put a condom on" and "Pope protects pedophile priests." Organizers said they expected 10,000 people, and thousands were seen marching through London. Police declined to give a crowd estimate. Even a crowd of a few thousand would make it the largest protest against Benedict since his election in 2005. Benedict was miles away at the Vatican's apostolic nunciature in Wimbledon, having lunch and resting. There were increasing indications, though, that he would meet with British abuse victims before the day's end. The sex abuse scandal has clouded Benedict's state visit to this deeply secular nation with a centuries-old history of anti-Catholic sentiment.