While Leo has called for caution on artificial intelligence several times since his election in May 2025, his latest warning comes as Trump faces a backlash over a now-deleted AI-generated post seemingly depicting the US leader as Jesus.

After holding Mass in the stifling heat in Cameroon’s economic capital Douala for more than 120,000 joyous worshippers — the biggest event of his landmark Africa trip so far — the leader of the world’s 1.4 billion Catholics sounded the alarm over the perils of the technology.

“The challenge posed by these systems is greater than it appears: it is not just about the use of new technologies, but about the gradual replacement of reality by its simulation,” he said in a speech to teachers and students at the Catholic University of Central Africa in the capital Yaounde.

“In this way, polarisation, conflict, fear and violence spread. What is at stake is not merely the risk of error, but a transformation in our very relationship with truth.”

It marks the pontiff’s latest outspoken intervention on his 11-day Africa tour that has seen him abandon his previous restraint to deliver impassioned pleas for world peace – and tussle with fellow American Trump.

‘Handful of tyrants’

After the pope criticised the US-Israeli war with Iran, Trump lashed out at Leo, branding him “weak on crime and terrible for foreign policy”.

He then posted an AI-generated image seemingly depicting himself as a Christ-like figure, which he later deleted after religious leaders accused him of blasphemy.

And shortly after Leo denounced the “handful of tyrants” ravaging the world in a speech on Thursday, the US president said the pope needed to understand the realities of a “nasty world”.

Far from the Trump broadsides, Leo has been greeted by adoring, singing-and-dancing crowds wherever he has gone in Cameroon.

Some of Friday’s throng had travelled far or arrived the previous night in the hope of catching a glimpse of the pope at his Douala Mass.

Waving “branches of peace” and Vatican flags, to lively choral music punctuated by percussion, the crowd chanted “Long live the pope!” as Leo arrived in a popemobile at the esplanade outside the Japoma Stadium.

“It’s the achievement of a Christian lifetime. When I was little, I thought you couldn’t see the pope with your own two eyes,” Marguerite Tedga, 72, said after waiting all night with friends from her parish.

Edith Fifi, a 25-year-old beautician, said seeing the pontiff gave her “a feeling of deliverance”.

“I was deeply moved by his message, and what I remember most is his call for sharing,” she said.

But some Cameroonian Catholics had feared that Leo’s visit could help President Paul Biya, who has ruled with an iron fist since 1982, burnish his image.

Douala, one of central Africa’s largest ports, was among the cities to see a violent crackdown on demonstrations against the re-election in October of a man who at the age of 93 is already the world’s oldest head of state.

Witnesses have reported that the security forces fired live rounds into the crowds. The authorities have acknowledged dozens of deaths without giving a precise toll.

No to ‘plunder’

Without mentioning Trump or Biya by name, Leo has delivered unusually pointed speeches across his African tour — ignoring Catholic US Vice President JD Vance’s call to “stick to matters of morality”.

In his speech on AI on Friday, the pope also condemned the “environmental devastation” caused by the extraction of the rare earths essential to the technology’s stunning growth — a cornerstone of the Trump administration’s approach to Africa.

And Leo also demanded an end to the corruption of a mining industry through which foreign powers — China foremost among them — reap the riches of Africa’s wealth while locals suffer.

After arriving in the country Wednesday, the pope urged Cameroon’s leaders to root out corruption and abuses carried out in the name of order — within Biya’s earshot.

The Catholic Church plays an important social role in Cameroon, where more than a third of the population of 30 million people are Catholic.

Leo wraps up his visit to the country with a Mass on early Saturday.

He was previously in Muslim-majority Algeria for a visit marred by two suicide bombings.

The pope heads on to Angola before wrapping up his 18,000-kilometre (11,200-mile) tour in Equatorial Guinea.