Pope Benedict arrived in Africa on Tuesday, where he said the continent's people were suffering disproportionately due to the global challenges of food shortages, financial crises and climate change.

After arriving in Cameroon on his first visit to Africa since becoming pope, the pontiff called on Christians to tackle violence, poverty, corruption and abuse of power, issues that have continually stifled the continent's progress.

The Pope was greeted by Cameroon's President Paul Biya, bishops from across Africa and a mix of local religious and political leaders before setting off in his popemobile, flanked by motorcycles, along streets lined with thousands of flag-waving supporters.

With the number of practicing Catholics dwindling in the developed world, Africa is seen as vital to the Church's future. But the relationship is not without controversy, mainly over the use of condoms in preventing AIDS, a disease decimating Africa.

At a time of global food shortages, financial turmoil, and disturbing patterns of climate change Africa suffers disproportionately, he told crowds on his arrival.

More and more of her people are falling prey to hunger, poverty and disease. They cry out for reconciliation, justice and peace, and that is what the church offers them, he added.

Some progress has been made in establishing democracy across Africa but Tuesday's resignation of Madagascar's President Marc Ravalomanana, who was forced out of power by the army and the opposition, underscored its propensity to conflicts and crises.

Many in Cameroon have called on the Pope to start his mission for peace and reconciliation by sending a strong message to his host, Biya, who has ruled for over 26 years.

Biya's time in power has been marked by accusations of high-level corruption and human rights abuses. The security forces this week destroyed street-side stalls that provided an income for thousands, in a bid to clean up the city.

I am glad that he is coming but he should be here for religion and not other things, said 29-year-old Calvine Noumbisi, who squatted at the side of the road selling rosaries, prayer books and incense rocks for a nearby church.

If he prays, blesses the country and tells the politicians to confess, it will help us, she added.

CANNOT REMAIN SILENT

While in Cameroon, Benedict will visit charities, meet Muslim leaders and attend a gathering of bishops trying to chart the Church's role in improving Africans' lives. Later in the week, he will go to Angola.

Although Cameroon and Angola are both resource-rich nations, where oil has flowed for many years and millions of dollars' worth of minerals have been dug from the ground, most of their inhabitants still live in grinding poverty.

We are happy. Jesus came for the sinners. Cameroon is ill so we are happy he has come to save us, said Robert Nguidjoi, who sang, danced and prayed at the St. Francois Xavier church.

A billboard in central Yaounde showed a photo of the Pope and Biya, with the words A perfect communion. But the Pope vowed to tackle sensitive subjects.

In the face of suffering or violence, poverty or hunger, corruption or abuse of power, a Christian can never remain silent, he said on his arrival.

But the Vatican's refusal to let Catholics use condoms remains controversial on a continent where AIDS has killed more than 25 million people since the early 1980s.

While medical workers advocate the use of condoms to help prevent the spread of AIDS, the Church insists on fidelity within heterosexual marriage, chastity and abstinence.

The problem cannot be overcome by distributing condoms. It only increases the problem, the pontiff said on Tuesday.

(Additional reporting by Tansa Musa in Yaounde; Editing by Daniel Magnowski and Katie Nguyen)

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