By Sarah Marsh and Philip PullellaSANTA CRUZ, Bolivia (Reuters) - Saying he too had made mistakes and sinned, Pope Francis on Friday urged inmates at one of Latin America's most violent prisons to shun gang violence and exhorted guards to treat them with dignity."The man standing before you is a man who has experienced forgiveness. A man who was, and is, saved from his many sins," the pope told hundreds of prisoners and their children on a visit to a place one long-time inmate likened to "Sodom and Gomorrah"."That is who I am. I don't have much more to give you or to offer you, but I want to share with you what I do have and what I love. It is Jesus Christ, the mercy of the Father," he said as two children wandered up to the stage and sat before him."I ask you, please, to keep praying for me, because I too have my mistakes and I too must do penance," he said.Guards secure only the perimeter of the sprawling, maximum-security Palmasola prison, while murderers and drug traffickers run its units, more shantytowns than prison wings, charging inmates for all aspects of their existence.The pope said that while guards and staff played an important role in reintegration they must respect the prisoners."It is their responsibility to raise up, not to put down, to restore dignity and not to humiliate; to encourage and not to inflict hardship," he said.At an emotional gathering on a scruffy sports field, head prisoner Leonidas Martin Rodriguez Delgado told the pope that when he arrived in 1997 it felt like the sinful biblical cities of Sodom and Gomorrah "because there was no rule of law".Pope Francis urged prisoners to shun rivalry and seek "genuine fraternity"."Do not be afraid to help one another. The devil is looking for rivalry, division, gangs. Keep working to make progress ... I have seen how pain does not stifle the hope deep within the human heart and how life goes on, finding new strength even in the midst of difficulties," he said.Palmasola is infamous for violence between factions. In one of the worst incidents, in 2013, at least 30 inmates were killed in section PC3, which houses the most dangerous.Since being elected the first Latin American pope in 2013, Pope Francis has continued a tradition he started when he was archbishop of Buenos Aires, visiting jails several times a year."I know that there are many things here that make it hard: overcrowding, justice delayed, a lack of training, opportunities and rehabilitation policies, violence," he said.Most of Palmasola's inmates have not been convicted of any crime. Nearly 90 percent of Bolivia's around 12,000 prisoners are awaiting trial, trapped by the Andean country's creaking justice system.WORLD OF ITS OWNFor the right price, inmates in Palmasola can buy anything: a cell, food, drugs, protection, prostitutes and prime 'real estate' from which to run a business. Without money, though, life is tough, and many prisoners sleep on the floor.The pope visited the relatively tranquil PC4 section, where laundry hangs from lines slung between ramshackle buildings, kiosks sell juice, and tables from a cafeteria spill out into a square containing a statue of Jesus Christ.Jose Luis Salas, a 42-year-old inmate and father of eight, said before the visit he hoped the pope would bring "some spiritual help to keep up the hope we will get out of here."Salas, who struggles to finance his family outside by making handcraft that he sells in the prison, said he has been in Palmasola for two years without trial on a theft charge.The chaplain of one of Palmasola's four churches, Father Leonardo Da Silva, has often denounced Bolivia's slow justice system."The Church goes where the state does not," he told Reuters before the visit.The pope was due to meet the country's bishops before flying to Paraguay for the last stop of his Latin American tour.(Additional reporting by Diego Ore; Editing by James Dalgleish)Join the conversation about this story Click here to read full news..