(CNN) -- At least nine people -- five soldiers, a police officer and three civilians -- died Saturday in what Colombia's president called a "terrorist" attack carried out by a storied rebel group.
Military authorities, national police and President Juan Manuel Santos blamed the morning attack in the nation's Cauca state on the Revolutionary Armed Forces of Colombia, known as the FARC. In addition to those killed, three soldiers, 12 police officers and 23 civilians were injured, according to the president's website.
"We have to continue to be on the offensive, not to give them a single minute of rest, not give them a single minute of truce so that they do not have the capacity to commit acts like this one," Santos said.
There was no immediate claim of responsibility for the blast.
The national police website posted audio from police Maj. Gen. Jorge Nieto saying, "All (evidence) indicates that there were cylinders camouflaged by food items inside of a vehicle." Nieto added that the attack occurred when residents were preparing for a farmer's market day in the municipality of Inza.
The FARC has been at war with the South American nation's government since the 1960s, a time marked by periodic bloodshed.
Santos was first elected in 2010 on a platform of continuing an offensive against the leftist guerrillas that have been at war with the government for decades, but he instead followed a different path by pushing forward with the peace process starting last year. He announced last month that he'd seek re-election against, among others, rival Oscar Ivan Zuluaga, who has called for an end to the peace talks and is against giving a political space to the rebels.
Santos said during an awards event Thursday in Bogota that Colombia "is a country decisively seeking peace, and advances in the direction of dialogue with firmness and prudence, without neglecting security for a single second."
On Saturday, the president condemned what he called a "cowardly" act and offered a reward of up to 30 million pesos ($15,500 US) for any information leading to those responsible.
He also insisted that the Colombian government wouldn't back down in the face of these and an estimated 500 other attacks carried out this year.
Said Santos: "If the FARC believe that these acts will get us to a cease-fire,... they are wrong, they are completely wrong beginning to end."