VATICAN CITY • Pope Francis heads to Africa this week for the riskiest trip of his papacy, defying danger with an open-topped popemobile and visits to a slum, refugee camp and mosque despite security fears following extremist attacks.

The Argentine pontiff will urge efforts towards peace, social justice and conciliation between Islam and Christianity on his travels to Kenya, Uganda and the Central African Republic (CAR) during the five-day trip from Wednesday.

His bodyguards will be working overtime in a region riddled with terrorist violence and following a spate of deadly attacks from France to Turkey and Mali by gunmen claiming to be acting in the name of Islam.

The 78-year-old, a self-appointed defender of the downtrodden, will give 19 speeches on his 11th foreign trip and meet victims of war, child soldiers and Aids sufferers, as well as those who are living in extreme poverty.

The Vatican has warned that the CAR part of the trip could be changed or cancelled entirely if security risks increase.

But Pope Francis is keen for it to go ahead, particularly the planned opening on Sunday of a "Holy Door" in Bangui's cathedral 10 days before the start of the Jubilee Year, a period devoted by the Catholic Church to forgiveness and reconciliation.

Before the CAR, he will visit Kenya and Uganda, where a respective 32 per cent and 47 per cent of the population are Catholic, and where the threat of attacks by Somali extremist group Al-Shabaab is ever present.

It will not be the first papal appearance in either country: The Pope's globe-trotting predecessor John Paul II travelled to Kenya three times, while Uganda holds the honour of having been the first African country to be visited by a pope, with Paul VI going in 1964.

AGENCE FRANCE-PRESSE