After cooking an evening meal for her five children, Suleyma Angelo Yepes, a juice seller, often dozes off while sitting on her porch in the La Playita neighbourhood of Buenaventura, Colombia. It is something she could never have imagined a few years ago.

“I can fall asleep and nothing will happen, thank God,” says Angelo Yepes, 39, as she watches children play marbles in the street. She smiles as she talks of the transformation of Puente Nayero, a ramshackle array of wooden houses on stilts once known as one of the country’s most dangerous neighbourhoods.

“It was horrible before, terrible” Angelo Yepes says. “You couldn’t go out at night, you couldn’t sleep, because there might be shooting. I was too afraid to let the children go to school.”

She holds out her hands at right angles to her body, to show the tremors she still has – the result of years living in terror on a street dominated by violent armed gangs.

Four years ago, Buenaventura found itself in the international spotlight after it was billed as the country’s most violent city. A Human Rights Watch report revealed how powerful successor groups of paramilitaries were terrorising poor neighbourhoods. Abductions and disappearances were widespread, and many people were driven from their homes.

The groups also restricted the movements of locals, recruited their children and forced small businesses to pay extortion money. Resistance was met with horrific acts of violence.

In Puente Nayero, the gruesome casa de pique, or “chop house”, where victims were tortured and dismembered alive, has been demolished. Community leaders still talk of the horror instilled by its presence.

But in April 2014, the community of about 300 families took a brave and unprecedented step towards wresting back control of their neighbourhood. Ignoring the death threats that they continue to face today, they formed a committee of activists and, with the help of the Inter-Church Justice and Peace Commission and Christian Aid, declared an urban “humanitarian space”, denouncing armed violence.

The Inter-American Commission on Human Rights granted precautionary protection measures to the families of Buenaventura and ordered the Colombian state to adopt measures to safeguard their lives. They were granted 24-hour protection.

Today, the results of this unique experiment are clearly visible. Two police officers sit at a table at the entrance to the street, while an armed soldier in fatigues leans against a wall further up, chatting to residents. As children play happily on the street, well after dark, young residents are gathered under a makeshift wooden shelter near the water’s edge, playing cards and dominos. Locals have begun to invest in their homes. Some of the wooden and corrugated iron shacks have been replaced with brick and cement buildings, and one house boasts an extravagant spiral staircase.

As a soldier patrols, a young woman combs the hair of a child on a street in Buenaventura. Photograph: Federico Rios/Christian Aid

Most remarkably, a community formerly under siege from armed gangs is now a haven for regional activists who face such serious death threats that they are afforded armed guards by the national authorities.

Two years after a peace accord between the government and Revolutionary Armed Forces of Colombia guerrillas, that ended a 50-year war in which 220,000 people died, violence is at an all-time low in the country.

Some officials have played down Buenaventura’s security problems by highlighting a huge drop in its homicide rate: from a nation-leading 121 per 100,000 inhabitants in 2006, to just under 14 a decade later.

But activists say these figures are unreliable given the number of “disappearances” in the city, one of the most deprived in Colombia, despite its position as the country’s most important port.

Community organisers and activists remain at particular risk, with 300 killed since 2016. They are sent here to keep them safe.

Meanwhile, the violence caused by groups vying for control of land in Buenaventura’s rural areas continues. A UN report last year found the rural areas of Buenaventura, in Valle del Cauca, to be among the most affected by increasing internal displacement, where entire communities are forced to flee their homes. Afro-Colombian and indigenous communities account for 10% and 3% of the country’s 7.4 million internally displaced persons.

Across the street from Angelo Yepes lives Melia Beveros Angelo, 26, a mother of four from the Naya community who is one of at least two women afforded protection here after receiving threats relating to an incident in which four men disappeared.

“I’ve only been here a short time” says Beveros Angelo. “It is not our own place. But we all know each other and I feel more or less safe”.

Fernando Rodallega, a young man in his 20s who works nightshifts at the port, says: “Thank God the humanitarian space was established. It has improved things a lot. So many families have begun to invest in their houses. You can see for yourself, there are children playing in the street”.

‘Thank God the humanitarian space was established’: Fernando Rodallega (seated with blue T-shirt) outside his home in Buenaventura. Photograph: Federico Rios/Christian Aid

Rogallega, who has lived here all his life, says that before the street was set up as a safe zone he often had to sleep elsewhere before going to work, because it was too dangerous to venture out at night.

“There were shootings and a lot of violence and I feared for my life” he says. “We did consider leaving. But I had a steady job.”

Father Jesús Alberto Franco, a leader of the Inter-Church Justice and Peace Commission, was instrumental in bringing the concept of humanitarian zones to Colombia’s rural areas. “When we first came here, we saw chaos and violence,” he says. “But we quickly saw that the violence wasn’t chaotic: it was organised and defined.”

Franco says the construction of a freshwater port, and plans to bring in more tourism and other business, has been a factor in the displacement of Afro-Columbian people from the coastline, as well as people from the lower stretches of the Calima and San Juan rivers. The area also has long-standing crime problems, due to drug trafficking because of its position as a Pacific port. Brute force is used to threaten and displace poor people who stand in the way of development, says Franco. “With such violence, no one talks.”

The humanitarian space is the first of its kind in an urban area, Franco says. Unlike the “zones”, which do not allow armed actors of any kind, it allows members of the military to patrol.