Two girls were killed and 40 injured on Saturday in a crush when the gates of a stadium in the Angolan capital Luanda were opened for 30,000 youths who had come to hear him speak. "I offer my sympathies to their families and friends, and my deep sorrow, because they were coming to meet me. I pray for the wounded," Benedict said at the start of a giant Mass service on Sunday which drew hundreds of thousands. The crowds cheered as the pope drove to a giant steel stage in a field that organisers said could hold two million people but was not completely full. The event was far more orderly than the raucous reception the pope received on Saturday. Keenly aware of the tragedy, organisers promptly escorted rowdy youths off the field. The last deadly stampede during a papal visit was in 1980, when nine people died in Kinshasa during a service by Pope John Paul II. But most people followed the service, singing hymns in the blazing heat, with women in pink sarongs bearing the face of the pope and Jesus, while others had the Benedict's image emblazoned on their T-shirts and baseball caps. Health workers at a medical tent said they treated about 400 people for heat stroke, including two who were sent to hospital. Benedict used his homily to urge Angolans to rebuild their nation after decades of civil war, following on his earlier calls for African leaders to step up the fight against poverty and corruption. "Tragically, the clouds of evil have also overshadowed Africa, including this beloved nation of Angola," he said. The pope denounced "the evil of war, the murderous fruits of tribalism and ethnic rivalry," but encouraged Angola's Catholics "to be the builders of a better tomorrow for your beloved country." "It is to preach this message of forgiveness, hope and new life in Christ that I have come to Africa," he added. Angola is home to one of the oldest Catholic communities in sub-Saharan Africa -- the religion arrived with the Portuguese 500 years ago -- but now faces growing competitors for the faith of the nation. Organised evangelical churches, traditional faiths and home-grown sects are all growing in popularity, even though some of the shadier sects have been implicated in child abuse scandals and even human sacrifice. On Saturday, Benedict condemned the practice of witchcraft and urged Catholic clergy and laypeople to convert more people to the faith. About 55 percent of Angolans are still Catholic, and the Church remains one of the few strong national voices outside of government, running a radio station in Luanda known for broadcasting dissenting views. Local Church leaders hope the pope's visit will push Angola's government -- run by the formerly Marxist Popular Movement for the Liberation of Angola -- to allow Radio Ecclesia to broadcast nationwide. In a speech at President Jose Eduardo dos Santos's residence late Friday, Benedict urged African leaders to allow greater press freedom, as he made a stern call for the continent to do more to fight poverty and corruption. Dos Santos has ruled Angola for 30 years, and the country is ranked among the most corrupt in the world by Transparency International. The mass was the last major event of his two-nation tour, which began on Tuesday in Cameroon and sparked controversy before he even landed, when Benedict told reporters on the plane that condoms were aggravating the AIDS crisis. He returns to the Vatican on Monday.