Intelligence officials in Burundi are running secret torture and detention sites to silence political opponents of the nation's leader.
In 2016, a disturbing viral video posted on social media showed a red liquid pouring from a drain outside a home in Bujumbura's Kinindo region, in the African nation's west.
The political unrest was sparked over President Pierre Nkurunziza's decision to run for a third term in office — despite concerns over whether it violated the constitution.
The homeowner, Prosper Kaze, who fled the nation during those protests, was a member of the Burundian opposition.
"It's the place where I grew up, so I can't mistake it," Kaze told the BBC earlier this year.
Hundreds were killed during the 2015 demonstrations, and Mr Nkurunziza won the election by default after the opposition boycotted the vote.
The BBC spoke to a man who lived in the building before it was allegedly turned into a torture chamber.
The man, identified only as Pierre, claimed to have been held hostage there. He told the BBC prisoners would be called into a room and questioned by security officials.
If the police were not satisfied with their answers, they would torture them using electric cables to beat their hands and canes to hit their feet.
"If they wanted to question someone, they would call him and they would approach the 'Chief'," he told the BBC.
"If they were not satisfied with your answer, they would torture you. You would hand them your hands and they would beat you with electric cables, also they would cane you … while kneeling."
He said that, in December 2016, people would try to escape the house while police shouted: "Get those dogs — don't let them escape."
He claimed they also shouted instructions such as "bring sacks and stuff in those dogs and load them in the car".
"When they finally caught them, I could hear them (the prisoners) screaming in a way that suggested that they were being killed or being inflicted excruciatingly," Pierre said.
"They did not come back in the house after — I think they were killed."
A second man — identified only as Nathan — claimed to have worked as a guard at the property around the time the viral "blood" video went viral.
He claimed the three men were killed after being taken out of their room one night by a security chief who ordered for them to be beheaded.
Nathan claimed one man who tried to escape was caught and killed inside the main gate of the property. His body was allegedly then brought back inside the house where the other prisoners had been beheaded.
The network also spoke to the man whose family lived in the house — and who personally built the sewage system.
He identified the bathroom drain which connects to the gutter where the red liquid was filmed flowing in the viral video.
The BBC put these claims to Burundian authorities but received no response.
But an anonymous individual told the network that, while there is currently no political unrest in the country, the alleged killings are still taking place.
"Some people think that the country is safe now," Nathan said.
"I want to tell you this — this small respite is, for them, the best time to carry out the killings without anyone noticing it."
At least 21 alleged torture facilities have been identified by former prisoners and security agents across the country.
All have been reported to United Nations.