Santos ruled out a cease-fire, offered by the rebel group known by its Spanish acronym FARC, after a car bomb and mortar attack on a police station Dec. 7 killed at least eight people. The attack occurred as FARC and government negotiators continued talks in Cuba on reaching a peace deal.
More than 220,000 people have died in about 50 years of conflict between FARC and successive governments in Bogota.
Analysts say the timing of the three almost concurrent events is so odd that it may indicate divisions emerging within FARC about the decision to enter into talks with the Santos administration as part of a bid to secure political representation for the group's aging rebel leaders.
Officials say FARC influence is waning among Colombia's poor and disgruntled youth and villagers. Colombia's improved economy has also helped to wean some of the FARC rank and file away from a life of endless armed struggle and violence.
Rebel representatives and government negotiators remain divided on the extent of political rehabilitation likely to be offered the rebels.
The next round of talks in Havana will focus on FARC links with drug cartels and its own finances, believed to be backed up by clandestine narcotics operations as well as FARC's reported participation in drug smuggling across Latin America to North America.
Both sides agree progress has been made on two of the six major points -- land reform to help Colombia's dispossessed farmers and FARC participation in Colombia's mainstream politics. Questions of disarmament, illicit drugs, rights of the victims of FARC activity and details of a peace deal still need to be resolved.
Colombia also has to deal with political rehabilitation of the rebels to satisfy various international law enforcement agencies, including U.S. authorities, that have FARC leaders on terrorist lists.
Santos described the attack on the police station as cowardly, irrational and "demented."
"If the FARC believe that with acts like this they are going to lead us to a cease-fire, which is also what they are saying, they are totally mistaken," Santos said during a visit to the town of Inza in Colombia's Cauca state, where the attack took place.
The government would consider a cease-fire only when a peace deal has been reached, he said.
"We will continue attacking them. The offensive will continue," Santos added.
FARC offered a 30-day cease-fire beginning Dec. 15. But it also claimed responsibility for the Inza attack.