Pope Francis lashed out at wealthy minorities who hoard resources at the expense of the poor as he visited a crowded Nairobi slum on Friday, wrapping up the first-leg of a three nation tour.
The 78-year-old pontiff was given a rapturous welcome as he arrived in Kangemi, which is home to more than 100,000 people who live in shacks without sewerage, including 20,000 who belong to the local Catholic parish.
"These are wounds inflicted by minorities who cling to power and wealth, who selfishly squander while a growing majority is forced to flee to abandoned, filthy and run-down peripheries," he told crowds in the slum which is on the outskirts of the Kenyan capital.
Wild singing and ululating erupted as Francis' arrived in Kangemi, his popemobile weaving through a sea of tin-roofed homes.
Speaking at the local Catholic church, Francis -- whose visit to the shanty town was a highlight of his three-day visit to this east African nation -- condemned the "dreadful injustice of urban exclusion."
"I am here because I want you to know that I am not indifferent to your joys and hopes, your troubles and your sorrows," Francis told the packed congregation at the church of St Joseph the Worker.
"I realise the difficulties which you experience daily. How can I not denounce the injustices which you suffer?"
People arrived long hours before dawn in the hope of catching a glimpse of the pope, who has made humility and help for the impoverished a hallmark of his tenure.
"It is once in a lifetime," said Edward Mwaniki, who comes from Kangemi and who waited for hours with his wife and three sons. "It is an honour to be here being a Catholic."
Francis criticised the lack of "infrastructures and basic services", including sewerage, electricity, good roads, school and hospitals in a key address just hours before he leaves for Uganda and the Central African Republic.
"They are a consequence of new forms of colonialism... countries are frequently pressured to adopt policies typical of the culture of waste," he added.
The pope went on to meet young people at Kasarani national stadium, where US President Barack Obama gave a keynote speech when he visited Kenya in July.
After arriving in Nairobi on Wednesday on his first-ever visit to Africa, the pope celebrated a giant open air public mass and spoke forcefully about the dangers of radicalisation and climate change.
"Experience shows that violence, conflict and terrorism feed on fear, mistrust, and the despair born of poverty and frustration," he said after arriving on Wednesday.
The fight against poverty has been a key theme of his visit, one that he picked up again before Thursday's mass on meeting leaders from different faiths.
"All too often, young people are being radicalised in the name of religion to sow discord and fear, and to tear at the very fabric of our societies," the pope said.
He also visited the United Nations headquarters in Nairobi, issuing a stark environmental message in which he warned it would be "catastrophic" if agreement is not reached at a key UN climate change summit which begins in Paris on Monday.
"We are confronted with a choice which cannot be ignored: either to improve or to destroy the environment," he said.
Thousands of people queued through the night braving torrential downpours to take part in Thursday's mass. But the numbers fell far short of the million people Catholic officials had expected to attend the service, with the weather likely keeping many away.
Pope Francis leaves Kenya mid-afternoon for Uganda where he will spend two days before continuing on to Central African Republic, a country wracked by sectarian conflict.
Security has been ratcheted up for the landmark visit over fears for his safety.
Islamist rebels have staged a string of attacks in Kenya, including the April massacre at Garissa university in which 148 people died, and the 2013 assault on the Westgate shopping mall that killed 67.
But Francis has shrugged off fears for his safety, joking that he was "more worried about the mosquitoes."