SAN CRISTOBAL DE LAS CASAS, Mexico (AFP) -- Pope Francis reached out to Mexico’s long-marginalized indigenous population on Monday, asking for forgiveness over their exclusion as he celebrated an open-air mass in native languages in impoverished Chiapas state.

While Chiapas is the country’s least Catholic state, tens of thousands of people packed into a sports field for the mass held under a papal decree that finally allowed Catholic liturgy in native languages.

Women wearing colorful embroidered dresses led biblical readings and hymns in the Chol, Tzotzil and Tzeltal -- all languages of the indigenous Maya people of the region.

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 organized way, your people have been misunderstood and excluded from society,” the 79-year-old Argentine-born pontiff said.

“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 Monday that the planet had much to learn from indigenous groups, especially their harmony with nature amid “the greatest environmental crises in world history.”

Around 30 percent of Chiapas’ population does not speak Spanish, the language of the colonial power that conquered Mexico in the 16th century, exploited indigenous people and sought to convert them to Christianity.

Francis already apologized for the church’s colonial-era crimes during a trip to Bolivia last year.

While Mexico’s early 20th century revolution sought to end land oligarchies, indigenous groups remain among the poorest in the country to this day and feel abandoned by the government.

The continuing plight of indigenous groups triggered a revolt by Zapatista rebels who sought more autonomy for them in 1994.

“Long live the pope of the indigenous people!” some shouted from the roofs of their homes as the pope arrived at the field, where a replica of the yellow facade of the city’s cathedral served as background to the large stage.

“I’m very happy because few people speak Spanish in my village and now they can receive the body of Christ in their language,” said Mariano Perez, a 33-year-old Tzotzil who attended the mass wearing a rancher hat.

While Mexico is the world’s second most populous Catholic nation after Brazil, with 82 percent of its population of 122 million identifying with the religion, only 58 percent are loyal to the Vatican in Chiapas.

“If the church is to stop the hemorrhaging of indigenous (populations) in Chiapas and across Latin America, it must offer more masses in indigenous languages and recruit indigenous priests who are very small in numbers,” Andrew Chesnut, religious studies professor at Virginia Commonwealth University, told AFP.

The pope’s visit comes in the middle of an intense, five-day trip that he has used to speak out against crime and corruption.

After the mass Francis visited San Cristobal’s cathedral.

He also visited the tomb of Samuel Ruiz, a bishop who defended the Mayan people and acted as mediator between the government and the Zapatista guerrilla movement that rose up in 1994.

Lingering tensions over the state’s social problems reemerged last week, when protestors spray-painted the words “we don’t want the pope, we want justice” on the cathedral’s yellow walls.

But the demonstrators dispersed over the weekend and authorities repainted the cathedral.

“We know that the government wants to hide things or make it seem that everything is all right,” said Octavio Gomez, a 45-year-old Tzeltal from a nearby village. “There are problems: Poverty, marginalization, displaced people.”

In San Cristobal, a family presented plans to build two new shelters for migrants in a region that is a gateway for Central Americans who risk their lives in a gang-infested journey to the United States.

The first Latin American pope -- himself the son of Italians who migrated to Argentina -- urged Mexicans during another mass on Sunday to build a nation where “there will be no need to emigrate in order to dream.”

But Alejandro Solalinde, a priest known as an activist for migrant rights, said that while the pope has made “migrants his pastoral priority,” his message will “not change the heavy-handed public policy” on migration.