Colombian special forces edged into guerrilla-controlled territory near the border with Venezuela Tuesday, trying to reassert state control amid violence that has forced 20,000 people to flee their homes.
The mountainous northeastern Catatumbo region has been the epicentre of a sudden surge in fighting between armed leftist groups vying for territory and control of lucrative coca plantations and trafficking routes.
Over six days, the bloodshed has killed more than 100 people across three regions.
But it is the situation near the border that prompted the government to declare a state of emergency and deploy some 5,000 troops.
Special forces deployed to the town of Tibu on Tuesday pushed out from urban strongpoints in a convoy of camouflaged armoured personnel carriers.
It was a tentative show of force, designed to convince sceptical locals that the government is back in charge and that some of the worst violence Colombia had seen in years was being contained.
For many Colombians, the recent bloodshed carries echoes of a civil war that killed 450,000 over more than half a century and made the country a byword for armed violence.
In addition to the 20,000 people displaced, the United Nations on Tuesday reported about 30 people had been kidnapped and 1,000 trapped in their homes by the violence.
On the outskirts of Tibu, government soldiers set up temporary posts on crumbling asphalt roads flanked by thick vegetation.
Troops -- warned by commanding officers to "remember, someone is waiting for you back home" -- nervously eyed the occasional rumbling truck or van that broke the jungle silence.
Others, with fingers close to the trigger, practised manoeuvrers or carried out foot patrols on empty lanes partially reclaimed by the equatorial forest.
Security officials say this spasm of bloodshed was caused by rivalry between Revolutionary Armed Forces of Colombia (FARC) dissidents and the National Liberation Army (ELN).
In empty settlements around Tibu, soldiers found ample evidence of who is usually in charge -- and of the rivalries between the two armed groups.
Stickers on sheds and shops celebrated late commanders of the once powerful FARC -- a Marxist group that signed a peace accord almost a decade ago.
On the same empty streets, scores of buildings were daubed with graffiti declaring "the ELN is present" or vowing to seek "liberty or death".
Most FARC members laid down arms from 2016, but dissident factions have continued to thrive in pockets of the country, enmeshing themselves in organised crime and the lucrative drug trade.
The ELN believed to number 6,000 fighters, has occasionally flirted with peace talks before walking away.
Experts say the ELN's leadership has been troubled by the FARC factions' growth in the region.
UN chief Antonio Guterres called Tuesday for Colombian non-combatants to be protected amid the fighting, urging "an immediate cessation of acts of violence against the civilian population."
