Pope Benedict XVI celebrated Mass Sunday with hundreds of thousands of Angolans and decried the "clouds of evil" over Africa that have spawned war, tribalism and ethnic rivalry that he said condemned poor people to virtual slavery.

The biggest crowd of Benedict's first pilgrimage to Africa turned up in sweltering heat for the open-air service on the outskirts of Angola's seaside capital, Luanda. It was the last major event of his seven-day trip, which ends Monday.

"How true it is that war can destroy everything of value", said Benedict, wearing a pink cape and mopping his brow with a white handkerchief.

Evils in Africa have "reduced the poor to slavery and deprived future generations of the resources needed to create a more solid and just society," he said during the Mass under a pink altar in a tent on a huge vacant lot near a cement factory.

Angolans have been enslaved, subjugated and at war almost nonstop since Portuguese colonizers brought the first Catholic missionaries in 1491. Many of the slaves taken to Brazil, for example, came from Angola.

The Catholic Church was an ally of the colonizers who discriminated against the people until independence from Portugal in 1975, when civil war erupted, in part fueled by the country's oil and diamond wealth.

Some 15,000 died, including missionaries, before the war ended in 2002 but its scars still are evident among the many people who lost limbs in one of the most heavily mined countries in the world.

A Marxist revolution also has left scars, though the country's president for 30 years, Eduardo dos Santos, abandoned communism and improved relations with the church from the late 1980s.

Critics say last year's massive election victory was marred by fraud and corruption and that the pope had to be wary of allowing his visit, sponsored by the state, to be seen as legitimizing an authoritarian regime. The bishops in Angola twice have denounced the government for leaving its people mired in poverty while leaders enrich themselves off oil and diamonds.

Since he arrived on Friday from Cameroon, the pope has met with dos Santos and spoken out against corruption in Africa, the continent with the fastest-growing Catholic population in the world.

Before Mass Benedict offered his condolences to the families of two 20-year-old women trampled to death in a stampede at a Luanda stadium before a youth event he addressed on Saturday.

He also wished a speedy recovery to some 40 people injured in the crush. Dozens of others collapsed and were treated at the site for heat exhaustion. The Vatican's No. 2 official, Cardinal Tarcisio Pertone, will visit the injured in hospital, said Vatican spokesman the Rev. Federico Lombardi.

People carried parasols and stools amid the hooting cars and motorbikes making their way to see the pope. Some men hoisted children onto their shoulders and mothers strapped babies to their backs.

Even before he landed in Africa, the pope provoked protests by telling reporters on his chartered Alitalia jet that condoms were not the answer to Africa's severe AIDS epidemic, suggesting that sexual behavior was the issue.

He condemned sexual violence against women, but also chided the 45 African countries including Angola that have approved abortion in cases of rape or incest or when a mother's life is in danger.

Lombardi quoted local officials saying there were a million people at the Mass. The number could not be independently confirmed.