YAOUNDE, Cameroon (AP) — Pope Leo XIV is marking the halfway point in his four-nation tour of Africa with a day focused on encouraging Cameroon’s young people. Leo was travelling Friday to Douala, Cameroon’s main port city, to celebrate Mass. The Vatican predicted some 600,000 people would turn out for the liturgy, the biggest crowd Leo is expected to draw on his 11-day, four-nation trip through Africa. Later Friday back in the capital Youande, Leo had an appointment with students, professors and administrators at the Catholic University of Central Africa. Popes have often used such encounters, especially in the developing world, to rally young people to persevere in the face of poverty, corruption and other challenges.