NAIROBI, Kenya — Pope Francis wants to bring a message of peace and reconciliation to an Africa torn by extremist violence, but security concerns are so high that he might be forced to make changes to his itinerary for the final leg of the trip.

Francis left Wednesday for his first-ever visit to the continent, a whirlwind pilgrimage to Kenya, Uganda and the Central African Republic that marks the first time a pope has flown into an active armed conflict: the 2-year-old spiral of deadly violence between Christian and Muslims in the Central African Republic.

On the eve of the departure, the Vatican spokesman, the Rev. Federico Lombardi, insisted that there were no new worrisome threats and that the pope planned to carry on with his program, as scheduled. But in a sign that the Vatican was on alert, Francis’ own chief bodyguard made a last-minute visit to Bangui this week to get the latest on-the-ground security updates, and will only meet up with the pope once he lands in Nairobi on Wednesday afternoon.