"The indications are that those responsible are the ELN, the evidence so far is in this direction," the president said yesterday after a security meeting at his palace, accusing the ELN of trying to "provoke fear and cause terror."
The National Liberation Army (ELN) is Colombia's second-largest guerrilla group, after the FARC, and is in preliminary peace talks with the government, though little progress has been made.
The low-intensity blasts Thursday may have been an attempt to influence the talks in some way, Santos said.
The explosions were blamed on a criminal gang that operated for the ELN.