MEXICO CITY—Exacting retribution for Catholic explorer Hernando Cortez's destruction of their civilization, Aztec extremists cut out visiting Pope John Paul II's heart in a ritual ceremony Monday. "For nearly 500 years, we have been brutally oppressed by the Catholics, enduring slavery, inquisition, rape, disease, forced conversions and random terror," said Aztec high priest Xalpatlahuac, holding aloft the still-beating heart of the pope, who was making his fourth trip to Mexico since ascending to the papacy in 1979. "In the name of all those who have died, I sacrifice this heart to the sun god Huitzilopochtli." The 78-year-old Polish pontiff was riding through the streets of downtown Mexico City in his popemobile when the extremists seized him and carried him off to a nearby Aztec pyramid. He was then pinned down by four priests, and, after a brief struggle, his chest was carved open with a sacrificial obsidian knife. The Catholic Church has not responded to the extremists' demand that $14 billion in plundered Aztec gold be returned.