Luanda  - In what was billed as the high point of his three- day visit to the southern African country, Pope Benedict XVI celebrated an open-air mass Sunday in Angola's capital Luanda in front of hundreds of thousands of worshippers.

Benedict was joined by southern African bishops in saying the mass on the Cimangola Esplanade at the entry to the city.

The celebration was overshadowed by the deaths on Saturday of two youths in a stampede Saturday at a sports stadium in Luanda, where the pope addressed thousands of youth.

Italian media reported that two young people were killed in the crush of thousands of people trying to get into the stadium. Another eight people collapsed because of the crowding and heat and were injured.

Rev Federico Lombardi, the Vatican spokesman, said the pope was "pained and concerned" at the deaths.

Sunday's mass is the last big event in the pope's first visit to Africa as pontiff, which began last Tuesday in Cameroon and has been overshadowed by his remarks about the role of condoms in preventing HIV infections. His visit, which took in just Cameroon and Angola, ends Monday.

On the plane to Cameroon the pope said condom use was not the answer to the spread of the pandemic in Africa - remarks blasted by the health fraternity as a major setback to their prevention efforts.

In the oil-rich former Portuguese colony of Angola, which suffered a devastating civil between 1975 and 2002, the pope has spoken out about corruption and high levels of inequality.

He also called for the further evangelization of Africa, the continent where the Catholic Church is growing the fastest. dpa