Colombia's President Juan Manuel Santos ordered the resumption of bombing raids against FARC guerrillas on Wednesday after a rebel attack killed 10 soldiers, heating up a war that had seen a tentative cessation of hostilities.
As part of peace talks with the Revolutionary Armed Forces of Colombia (FARC), Santos last month stopped air raids on rebel hideouts in recognition of a unilateral ceasefire declared in December by the insurgent group.
But the relative calm was shattered when the FARC ambushed the soldiers in rural southwestern Cauca province in the early hours of Wednesday, hurling grenades and firing on them as they took shelter in a covered sports field, the army said.
"This incident was a product of a deliberate attack by the FARC, it was not a coincidence and this implies a clear rupture of the promise of a unilateral ceasefire," Santos said after meeting with his defense team in the city of Cali.
"I have ordered the armed forces to lift the suspension of bombings on FARC camps."
Santos said the attack, which also killed a FARC fighter, would not go unpunished. At least nine government troops were confirmed injured.
The FARC called the incident a legitimate case of self-defense in reaction to an offensive by government troops.
"We expressly call on the government to maintain a cool head right now and not adopt any measures that could put in danger the advances we have made in peace talks," the FARC said in a statement issued in Havana, the site of two-year-old peace talks.
"It's absurd that people keep dying on both sides," the FARC said, repeating its call for a bilateral ceasefire.
FARC leader Pablo Catatumbo told Reuters in Havana the group regretted the events, which were not "premeditated."
Although it is unlikely to derail the peace talks in Cuba, the clash is the first significant attack blamed on the FARC since their ceasefire declaration.
Talks were suspended last year after the rebels kidnapped an army general and several soldiers. They have since been freed and talks resumed.
Santos has resisted FARC calls for a bilateral ceasefire, saying the rebels were not to be trusted after they exploited a truce during a previous peace process more than a decade ago to regroup and build up military strength.