Bogotá: Since January 16, the guerilla group ELN and offshoots of the former militant organisation FARC have been fighting each other in the Catatumbo region in the northeast of Columbia near the border to Venezuela. At least 80 people have died so far in the violence.
At least 20 more people have been killed in clashes in the Amazonas region in the south of the country between rival splinter groups of FARC.
According to the Colombian military, almost 20,000 people have fled their homes for safer areas amid the extreme violence.
"They have pulled people from their houses and cruelly murdered them," army commander General Luis Emilio Cardozo said in an internet video. "It is our job as the national army to stabilise the region."
UN Secretary General Antonio Guterres has called for an "immediate cessation of acts of violence against the civilian population," said UN spokesperson Stephane Dujarric. "The secretary-general is deeply concerned about the recent violence in the Catatumbo region of Colombia," Dujarric said.
The rival left-wing extremist groups in the Catatumbo region are seeking to gain control over human trafficking, the weapons trade, illegal mining, the cultivation of drugs and the cocaine trade.
The region is seen as strategically important, as drugs can be transported out of the country from there.
Daniel Parra, a researcher for the Peace and Reconciliation Foundation in Cucuta in the northeast of Colombia, says he cannot say precisely what has triggered the current clashes between the ELN and the FARC splinter groups.
"Some national media have cited military intelligence that everything happened after the loss of a cocaine delivery and the murder of an ELN head of finance," he told DW. "But we know nothing for certain about why this armed confrontation broke out."
According to Roberto Garcia Alonso, a professor for law and politics at La Sabana University, the basic reason for the present violence is clear: Drugs.
"The fight for territorial control and the drug trade, which have always been central elements in this conflict, is putting more and more pressure on this border region, which serves as a corridor for the drug trade with Venezuela," he said.
There have been armed conflicts between leftist guerilla groups, drug gangs, right-wing paramilitaries and the army in Colombia since the 1960s, leading to the deaths of hundreds of thousands of people.
Some 7 to 8 million people were displaced, and some 80,000 Colombians are classified as "missing."
Who are the actors?
The Revolutionary Armed Forces of Colombia (FARC) were previously by far the biggest guerilla group in Colombia. In 2016, they signed a peace agreement with the government of the time. The FARC disbanded, but several splinter groups rejected the peace deal.
The so-called National Liberation Army (ELN) was founded in 1964. It was not involved in the peace agreement and is seen as the strongest rebel organization still active in Colombia.
What role does President Gustavo Petro play?
Gustavo Petro has been Colombia's head of state since mid-2022. When he took office, he promised to take up negotiations with all the country's armed groups with the objective of achieving a broad peace.
After the escalation of violence in the north of Colombia, Petro spoke of war crimes and stopped the peace negotiations with the ELN guerillas. He imposed a state of emergency and declared war on the ELN, writing on X: "The ELN has chosen the path of war, and that's what they will get."
Petro himself was once the member of an armed group, an urban guerilla organization called M-19.
What comes next?
It currently seems doubtful whether the peace process can be advanced in the near future.
"It is very difficult, because what is happening here is eating away at President Petro's already low popularity," Garcia Alonso said. "What is more, the policy of a comprehensive peace has not delivered any results."
For this reason, he said, it is not clear whether the government will continue on that path. The outbursts of violence are also causing the population to lose much of its trust in the peace process, according to Garcia Alonso.
Daniel Parra is also skeptical. At first, Petro announced that negotiations with the ELN would be suspended, and now one saw with amazement that war had been declared on the guerilla group, he said.
"This worries us greatly because an armed conflict between guerilla fighters and the police would just cause more victims, more murders, more killings. We are wondering how the police will proceed," he said.
But Parra is not holding his breath. The ELN has been carrying on an armed fight for 60 years, and Colombia's government has not succeeded in getting the better of the rebel organization with direct force in all that time, he said.