THE presidents of the Pacific Alliance countries—Chile, Colombia, Mexico and Peru—have held two meetings of the trade bloc in Colombia: one in Cali, the country’s third-largest city, and another (last month) in Cartagena, on the Caribbean coast. A more obvious destination would have been Buenaventura, whose port on the Pacific handles half of all Colombia's foreign trade. The facility represents a bright future of burgeoning commerce—with Colombia’s partners in the Pacific Alliance and with Asia.

A new report by Human Rights Watch, a non-governmental organisation, shows why the leaders chose other locations. The city of Buenaventura, home to 400,000 residents, is a throwback to the country’s dark past. It is Colombia’s most violent city. Most of the inhabitants live in poverty and fear, caught between two rival criminal groups, themselves successors to paramilitary organisations which formed to fight the country’s FARC guerrillas. These rival gangs control extortion rings and drug trafficking in the area.

More than 50,000 city residents have been forced from their homes in the past three years, fleeing extortion, death, and forced recruitment into one of the gangs. Around 150 people have been reported as forcibly disappeared. The mutilated body parts of at least a dozen people have been found washed up along Buenaventura’s shores, according to human-rights groups. In its report, Human Rights Watch said that victims of the criminal groups are often dismembered alive in what are known as "chop-up houses". Police have discovered four such houses in the city's poorest neighbourhoods this month.

“The situation in Buenaventura is among the very worst we’ve seen in many years of working in Colombia and the region,” says José Miguel Vivanco, Americas director at Human Rights Watch. “Simply walking on the wrong street can get you abducted and dismembered, so it’s no surprise the residents are fleeing by the thousands.”

The government has sent 700 additional troops to try to quell the violence in the city but residents say they need more than boots on the ground. With more than 80% of the population living in poverty, unemployment above 30%, unreliable supplies of electricity and water, and dismal road infrastructure, it is one of the country's least developed cities. Colombia has made great strides in recent years to reduce poverty: 47.4% of the population lived below the poverty line in 2004, and by 2013 that proportion had fallen to 30.6%. But for the inhabitants of Buenaventura the situation remains intolerably bleak.