SEOUL – Pope Francis continued his five-day trip to South Korea Saturday, proving that his reputation as a magnet for humanity extends to Asia too. His Saturday morning Mass drew a crowd estimated by the Vatican to be 800,000 to a downtown Seoul square, where the pontiff beatified 124 Korean martyrs from the 18th and 19th centuries.

Francis used the occasion to deliver a trademark plea for social justice, saying that the memory of past martyrs should call believers to acts of charity. The pope said that “alongside immense wealth, dire poverty is silently growing” and lamented that “the cry of the poor is seldom heard.”

The gap between rich and poor has been one theme of the South Korea trip, where strong economic growth from the 1960s to the 1990s made the country one of Asian Tigers but also created a new underclass.

His morning Mass brought Francis to a square that has been occupied for the last four months by family members of victims from the April sinking of the Sewol ferry that claimed more than 300 lives, most of them high school students on a field trip.

The disaster has sparked national outrage here, with the families demanding that the government of President Park Geun-hye adopt a law creating an independent criminal investigation.

Though a Vatican spokesman, said Francis would not get involved in “specific decisions” about the debate, he stopped his Pope-mobile in front of a section of the square occupied by the families, most of whom were brandishing yellow signs reading “We want the truth” in English and Korean.

The pontiff spent a tearful moment with Young-oh Kim, a Hyundai auto worker who lost his 17-year-old daughter in the April Sewol shipwreck and who’s currently on day 34 of a hunger strike.

Spiritually the focus this morning was on the martyrs, who died during various waves of persecution under Korean’s old imperial dynasty. Francis stressed the price they paid for preserving the faith.

“For many, this meant persecution, and later flight to the mountains, where they formed Catholic villages,” the pope said.

“They were willing to make great sacrifices and let themselves be stripped of whatever kept them from Christ – possessions and land, prestige and honor.”

The pontiff recalled that the founders of Catholicism in Korea were not priests or foreign missionaries but laity, who encountered the faith in China and brought it back home. He said that history illustrates the “dignity and the beauty of the vocation of the laity.”

Francis said the memory of those sacrifices calls to mind “countless anonymous martyrs” of today, “in this country and throughout the world.”

Anti-Christian persecution has been a growing concern for Francis, especially in Middle Eastern nations such as Syria and Iraq where war and a rising influence of Islamic radicalism has often made Christians targets.

Just before his departure for South Korea, Francis dispatched a special envoy to Iraq to express his concern for Christians and other minority groups driven from their homes by the new Islamic State.

The Mass Saturday morning was expected to be the largest public event on Francis’ five-day schedule in South Korea, and local officials spent much of the last several months trying to head off what some feared would be paralysis in downtown Seoul.

Cardinal Andrew Yeom Soo-jung of Seoul issued a special decree saying that just for Saturday, the entire city was considered part of the space in which the Mass was being celebrated, and anyone watching it on television would be considered to have taken part.

Yeom also asked that all of Seoul’s Catholic churches be open during the Mass and show it on television, so that faithful could watch it together.

Later Saturday, Francis was scheduled to make a controversial visit to the Kkottongnae charity center outside Seoul, which serves 5,000 disabled people and has been described as an icon of the church’s concern for the poor by supporters but derided by critics as a fund-raising scam.

While there the pope will also deliver the most pointed anti-abortion gesture of the trip, visiting a symbolic “cemetery” for abortion victims located on a field behind the charity center.