Dismembered bodies of prisoners and visitors were discovered in drain pipes at a jail in Colombia.

The remains of at least 100 dismembered prisoners and visitors were discovered at the La Modelo jail, which is located in Bogotá and is one of Colombia's largest prisons. Investigators said on Wednesday that the penitentiary is home to drug traffickers, paramilitaries, and Marxist rebels.

Body parts were also found in prisons in the cities of Barranquilla, Bucaramanga, and Popayan, according to Caterina Heyck, an investigator from the attorney general's office.

"The number of victims is unknown, but we know it's over 100 and could be considerably higher," Heyck told reporters. "Remains of prisoners, visitors and others were thrown in the drainage system."

Jails in Colombia are among the most overcrowded and violent prisons in the Latin American region. The penitentiaries contain leftist guerrilla members along with their right-wing paramilitary opponents.

Colombia Frees 30 FARC Terrorists

The Colombian government has agreed to free 30 members of the Revolutionary Armed Forces of Colombia or FARC.

The pardon comes during the ongoing peace talks between Colombia's government and the leaders of FARC in Havana, Cuba, where President Raúl Castro is serving as mediator. The leftist group has demanded the release of FARC terrorists who have exhibited illnesses.

Among those released from prison are former bodyguards, higher-level leaders and members captured during terrorist raids in rural towns. None of those freed from jail have authority within the FARC and have not been imprisoned for "grave crimes."

Colombia Imposes Stricter Law on Acid Attackers

Earlier this year, Colombian President Juan Manuel Santos signed a law that enforces tougher and longer sentences on acid attackers.

The law, which was approved by the Senate last November, decrees that those who "use any type of chemical agent" to hurt others will serve jail time between 12 and 20 years. The sentence, however, can go up to 50 years for those who permanently disfigure their victim.

The new law also aims to provide better state medical care to acid attack victims

Acid attacks have become a huge issue in Colombia over the past decade. Around 100 people -- the majority of them who are women -- are victims of acid attacks annually. Perpetrators can either be men or women, varying from angry neighbors to jealous lovers.

Acid attacks are most common in South Asia, but Colombia reported one of the highest rates per capita globally in 2012. Since 2004, 526 women and 361 men have suffered acid attacks across Colombia, according to the country's National Institute of Legal Medicine and Forensic Sciences.