The United Nations peace mission in Colombia on Monday condemned a spiral of violence engulfing the country, saying it had documented 33 massacres so far this year.
The mission, set up to monitor adherence to a 2016 peace deal with the former Revolutionary Armed Forces of Colombia (FARC) guerrillas, said it was investigating the deaths of 97 human rights defenders killed during the same period.
The violence was having a "serious humanitarian impact" in areas where illegal armed groups continued to operate, it said.
At least 13 people were killed in two separate incidents in the last week alone.
On Saturday, eight people were gunned down at a birthday party in Samaniego, in southwestern Nariño department, police told AFP.
Nariño borders Ecuador and is one of Colombia's main areas for growing coca leaves, the raw material for making cocaine.
Its strategic location makes it a favoured route for smuggling drugs north to Central America and the United States.
Meanwhile, authorities last Tuesday discovered the bodies of five Afro-Colombian teenagers in a sugar cane field near Cali.
Colombian and UN officials sounded a joint warning on Sunday about the deteriorating security situation in the country, despite a lockdown against the spread of the coronavirus in place since March 25.
Crime gangs are believed to be responsible for nearly 80 percent of massacres in Colombia this year, the vast majority of them occurring in departments with "illegal coca-producing enclaves," the UN human rights office said.
The UN has also recorded 41 murders of former FARC combatants in the first half of 2020, a 10 percent increase on the same period last year.
The UN defines a massacre as the killing of three or more people in the same event by the same group.
New drug-trafficking plan
The United States and Colombia on Monday announced the launch of a new joint plan to combat drug trafficking, including investments in areas affected by violence.
Colombian president Iván Duque and US National Security Advisor Robert O'Brien made the joint statement at the presidential palace in Bogotá, following a meeting. They did not specify the exact amount of resources allocated to the plan.
O'Brien said the US "will support all of Colombia's efforts... to ensure security in the country, to combat criminal organisations, some of which are transnational, and in doing so, we will help create the conditions for economic growth" in both nations.
Duque added that the US government "has not only seen the importance of... continuing to effectively combat drug trafficking and terrorism," but also of "combining those efforts... with quality investment in places that have been affected by violence."
They both presented the initiative as a new phase of the "Plan Colombia," an aid package from Washington aimed at combating drug trafficking in the South American country.
The US gave Colombia more than US$7 billion between 2000 and 2016 under the Plan Colombia agreement, but the money ended up being used to fight guerillas without eliminating the drug trade.