President Alvaro Uribe has flown to south-west Colombia to oversee a massive counterattack against leftist rebels. He made his move after 25 soldiers were killed on Saturday in a series of attacks across the country which shattered any notion that the insurgents were nearing defeat.
More than 1,000 troops backed by helicopter gunships hunted down several hundred rebels believed to be heading for the border with Ecuador, the army said.
In the deadliest day for the military since President Uribe came to power three years ago promising to crush the 40-year-old insurgency, as many as 300 members of the Revolutionary Armed Forces of Colombia (Farc) attacked oil wells near Puerto Asis and ambushed an army convoy, killing at least 19 soldiers.
Six more soldiers were killed when they fought rebels blockading a road in north-east Colombia. Another 19 soldiers who went missing during the combat in the south-west were found alive early on Sunday. Rebel casualty figures were not known.
"The murder of our soldiers pains us greatly," President Uribe said after crisis talks in Puerto Asis. "But to make concessions to terrorism undermines democracy."
For years, Farc guerrillas have slipped across the 400-mile border into Ecuador's northern jungle region to seek refuge from battle and to buy supplies. President Uribe said he intended to discuss strengthening border security with the Ecuadorean authorities.
Farc has killed more than 130 soldiers this year in some of its boldest attacks since peace talks collapsed in February 2002. The latest rebel offensive came after military commanders claimed that a US-backed, three-year military build-up ordered by President Uribe had forced the Farc into irreversible decline. Army officials say Farc comprises 12,000 fighters, down from 18,000 last year.
Analysts say Farc wants to undermine President Uribe's hopes of re-election next year by showing that his security crackdown has failed and that only a leader more sympathetic to the rebels can bring peace. The constitutional court has yet to decide whether Mr Uribe can seek a second term.
Colombia's drug-fuelled conflict pits the Farc and the smaller National Liberation Army against a handful of right-wing militias and government forces. More than 3,000 people a year have been killed.Reuse content