QUITO (Reuters) – Ecuador’s national police service said on Thursday that it had sent in 400 officers to restore order at one of the country’s largest prisons after a riot this week in which at least 116 inmates died and 80 were injured.

The Penitenciaria del Litoral was overthrown by rival gangs on Tuesday night. It is the most violent act of prison violence ever seen in South America.

The national police force of Ecuador (NYSE:) wrote that around 400 officers were conducting an investigation and search inside the prison to ensure security and order. They also posted a video showing officers wearing riot gear.

Later, the police added that they had found three explosives in the prison. It is located near Guayaquil, the largest city in the Andean nation. Late Wednesday, Ecuador’s prosecution office stated that it is still collecting data from the detention center.

The President Guillermo Lasso announced Wednesday that he plans to release funds and add security officers into Ecuador’s prisons in order to avoid another clash.

On Wednesday, the Inter-American Commission on Human Rights called Ecuador to stop criminal organizations from operating within its prisons.

The Washington-based Human Rights Wing of the Organization of American States tweeted that “IACHR” urged Ecuador again to conduct thorough investigations and take steps to prevent a similar incident.