Pope Benedict XVI, who is making his first papal visit to Africa, has said that handing out condoms is not the answer in the fight against HIV/Aids.
The pontiff, who preaches marital fidelity and abstinence, said the practice only increased the problem.
"A Christian can never remain silent," he said, after being greeted on arrival in Cameroon by President Paul Biya.
The Pope is also due to visit Angola on his week-long trip, where thousands are expected to attend open-air Masses.
Some 22 million people are infected with HIV in sub-Saharan Africa, according to UN figures for 2007.
This amounts to about two-thirds of the global total.
'Painful wounds'
HIV/Aids is a tragedy that cannot be overcome through the distribution of condoms, which can even increase the problem
Is Catholicism good for Africa?
According to Vatican figures, the number of Catholics in Africa has been rising steadily in recent years.
Baptised Catholics made up 17% of the African population in 2006, compared with 12% in 1978, the Vatican says.
Pope Benedict said on the eve of his trip that he wanted to wrap his arms around the entire continent, with "its painful wounds, its enormous potential and hopes".
HIV/Aids was, he argued, "a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms, which can even increase the problem".
The solution lay, he said, in a "spiritual and human awakening" and "friendship for those who suffer".
Speaking at the airport in Cameroon's capital, Yaounde, the Pope called on Christians to speak up in the face of violence, poverty, hunger, corruption and abuse of power.
Sexual abstinence
While in Africa, the pontiff is expected to talk to young people about the Aids epidemic and explain to them why the Catholic Church recommends sexual abstinence as the best way to prevent the spread of the disease.
He gave a similar message to African bishops who visited the Vatican in 2005, when he told them that abstinence and fidelity, not condoms, were the means to tackle the epidemic.
The BBC's Caroline Duffield, in Cameroon, says people in Yaounde have been energetically sweeping and cleaning everywhere in preparation for Pope Benedict's visit.
The Pope meets an imam in Yaounde
The Pope also met an imam from Cameroon's Muslim minority
The Pope will stay until Friday in Yaounde, where he will meet bishops from all over Africa who will be taking part in a meeting at the Vatican later this year to discuss the Church's role in Africa.
In Angola, which is still recovering from 27 years of civil war, Pope Benedict will meet diplomats posted in Luanda and is expected to urge the international community not to abandon Africa.
The pontiff is also due to hold private talks with political leaders in the two countries, both of which have been accused of corruption and squandering revenues from natural resources.
The pontiff, who preaches marital fidelity and abstinence, said the practice only increased the problem.
"A Christian can never remain silent," he said, after being greeted on arrival in Cameroon by President Paul Biya.
The Pope is also due to visit Angola on his week-long trip, where thousands are expected to attend open-air Masses.
Some 22 million people are infected with HIV in sub-Saharan Africa, according to UN figures for 2007.
This amounts to about two-thirds of the global total.
'Painful wounds'
HIV/Aids is a tragedy that cannot be overcome through the distribution of condoms, which can even increase the problem
Is Catholicism good for Africa?
According to Vatican figures, the number of Catholics in Africa has been rising steadily in recent years.
Baptised Catholics made up 17% of the African population in 2006, compared with 12% in 1978, the Vatican says.
Pope Benedict said on the eve of his trip that he wanted to wrap his arms around the entire continent, with "its painful wounds, its enormous potential and hopes".
HIV/Aids was, he argued, "a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms, which can even increase the problem".
The solution lay, he said, in a "spiritual and human awakening" and "friendship for those who suffer".
Speaking at the airport in Cameroon's capital, Yaounde, the Pope called on Christians to speak up in the face of violence, poverty, hunger, corruption and abuse of power.
Sexual abstinence
While in Africa, the pontiff is expected to talk to young people about the Aids epidemic and explain to them why the Catholic Church recommends sexual abstinence as the best way to prevent the spread of the disease.
He gave a similar message to African bishops who visited the Vatican in 2005, when he told them that abstinence and fidelity, not condoms, were the means to tackle the epidemic.
The BBC's Caroline Duffield, in Cameroon, says people in Yaounde have been energetically sweeping and cleaning everywhere in preparation for Pope Benedict's visit.
The Pope meets an imam in Yaounde
The Pope also met an imam from Cameroon's Muslim minority
The Pope will stay until Friday in Yaounde, where he will meet bishops from all over Africa who will be taking part in a meeting at the Vatican later this year to discuss the Church's role in Africa.
In Angola, which is still recovering from 27 years of civil war, Pope Benedict will meet diplomats posted in Luanda and is expected to urge the international community not to abandon Africa.
The pontiff is also due to hold private talks with political leaders in the two countries, both of which have been accused of corruption and squandering revenues from natural resources.
I'm not referring to anyone who has posted so far but some people still don't get it. Why do BBC report it as 'Pope tells Africa?' We aren't a country, we're a continent. What the Pope says in Cameroon is said in Cameroon. Sure, what he said was on the African continent but he sure as hell didnt even pass through Kenya or every other African country telling us to stop buying durex. 