Pope Francis asks forgiveness

Pope Francis reached out to Mexico's long-marginalised indigenous population on Monday, asking for forgiveness over their exclusion as he celebrated an open-air mass in native languages in impoverished Chiapas state.

Pope Francis waves to the crowd as he leaves after celebrating mass in San Cristobal de las Casas, Mexico.

While Chiapas is the country's least Catholic state, tens of thousands of people packed into a sports field in the southern city of San Cristobal de las Casas for the mass held under a papal decree that finally allowed Catholic liturgy in native languages.

Women wearing colourful embroidered dresses led biblical readings and hymns in the Chol, Tzotzil and Tzeltal languages. The pope himself said a few words in one of the native languages and cited Popol Vuh, an ancient Mayan text.

"On many occasions, in a systematic and organised way, your people have been misunderstood and excluded from society," the 79-year-old Argentine-born pontiff said after citing Popol Vuh, an ancient Mayan text.

"Some have considered your values, culture and traditions to be inferior. Others, intoxicated by power, money and market trends, have stolen your lands or contaminated them. How sad this is," he said.

"How worthwhile it would be for each of us to examine our conscience and learn to say, 'Forgive me!'" The pope said the planet had much to learn from indigenous groups, especially their harmony with nature amid "the greatest environmental crises in world history."