Colombia vowed "war" against left-wing guerrillas Monday, declaring a state of emergency and deploying thousands of soldiers to contain violence that killed at least 100 people and threatens to scupper the country's fragile peace process.
In just five days, bloodshed has been reported across three Colombian departments -- from the remote Amazon jungle in the south to the mountainous northeastern border with Venezuela, where fighting has displaced almost 20,000 people.
Analysts say the spasm of violence was caused by a turf war between rival militias, who see the faltering peace process as a threat to their unity and their profits from the ultra-lucrative cocaine trade.
President Gustavo Petro, who until now had staked his political fortunes on a strategy of de-escalation and dialogue, signaled the crisis would cause a shift in policy.
On Monday, he issued a defiant warning to leaders of the National Liberation Army, or ELN, which is said to have been behind border region attacks on rival leftist groups, killing 80 people.
"The ELN has chosen the path of war, and war they shall have," said Petro, before declaring a localized state of "internal unrest" and "economic emergency."
The declarations give local authorities the ability to restrict movement of people, among other measures.
Some 5,000 troops are already deploying to the border area, hoping to contain some of the worst violence Colombia has seen in years.
AFP reporters in the town of Tibu witnessed rows of heavily armed soldiers amassing in barracks and receiving orders from superior officers.
They have yet to engage guerrilla fighters directly or deploy to the most critical zones, where senior officers say violence is still raging.
Colombia has enjoyed almost a decade of relative peace, but pockets of the country are still controlled by assorted left-wing guerrillas, right-wing paramilitaries and drug cartels.
Over the weekend, terrified residents carried backpacks and belongings on overladen motorcycles and boats, or crammed onto the backs of open trucks to flee the border region.
Colombian military General Erik Rodriguez said more than 19,800 people have now amassed at shelters in Tibu and other towns.
Others crossed the border to Venezuela -- for some a return to a country from where they had fled economic and political upheaval.
"As a Colombian, it is painful for me to leave my country," Geovanny Valero, a 45-year-old farmer who fled to Venezuela, told AFP, saying he hopes the situation will be "sorted out" so he can return.
On Monday, Colombia's defense ministry also reported that 20 people had been killed in fighting between rival left-wing groups in the jungle-clad Amazon department of Guaviare.
The clashes involved rival FARC splinter groups -- left-wing guerrillas who, unlike the rump Revolutionary Armed Forces of Colombia, have not signed peace accords.
The clashes are a serious challenge for Petro who has backed a policy of "total peace" since he was elected in 2022.
In the face of fierce opposition, he launched negotiations with the various hardline armed groups that still control parts of Colombia.
Critics allege that his conciliatory approach has emboldened groups who are deeply involved in organized crime, and allowed them space to grow in power and influence.
A 2016 peace deal with FARC was hailed as a turning point in the six-decade-long conflict between Colombian security forces, guerrillas, right-wing paramilitaries and drug gangs, which has left nearly half a million people dead.
But dissident factions continue to control territory in several parts of Colombia, the world's biggest cocaine producer.
